Multi Problem Algebra
1) Calculate the following:
&i. Calculate $1^2 - 2^3 \times 3 + 8 \div 4 - (3^3 + 2)$:
$1^2 = 1$
$2^3 = 8$
$8 \times 3 = 24$
$8 \div 4 = 2$
$3^3 = 27$
Sum inside parentheses: $27 + 2 = 29$
Expression becomes: $1 - 24 + 2 - 29$
Simplify: $1 - 24 = -23$
Then, $-23 + 2 = -21$
Finally, $-21 - 29 = -50$
Answer: $-50$
&ii. Calculate $10 - 10 \times 10 + 10 - (10 + 10 \times 10)$:
First compute $10 \times 10 = 100$
Inside parentheses: $10 + 100 = 110$
Expression: $10 - 100 + 10 - 110$
Simplify: $10 - 100 = -90$
Then, $-90 + 10 = -80$
Then, $-80 - 110 = -190$
Answer: $-190$
&iii. Calculate $(3 - 5)^3 - 3 + 3^2 \times (5 + 1)$:
$3 - 5 = -2$
$(-2)^3 = -8$
$3^2 = 9$
$5 + 1 = 6$
$9 \times 6 = 54$
Expression: $-8 - 3 + 54$
Simplify: $-8 - 3 = -11$
Then, $-11 + 54 = 43$
Answer: $43$
&iv. Calculate $2 - (2 + 2 \times 2^2)^2 + 2 \div 2 + 2^2$
Calculate powers and multiplication inside parentheses:
$2^2 = 4$
$2 \times 4 = 8$
Inside parentheses: $2 + 8 = 10$
Square: $10^2 = 100$
$2 \div 2 = 1$
$2^2 = 4$
Expression: $2 - 100 + 1 + 4$
Simplify: $2 - 100 = -98$
Then, $-98 + 1 = -97$
Then, $-97 + 4 = -93$
Answer: $-93$
&v. Calculate $\left[11 - 4(2 - 33)\right] \div 37$
Calculate inside parentheses: $2 - 33 = -31$
Multiply: $4 \times (-31) = -124$
Inside brackets: $11 - (-124) = 11 + 124 = 135$
Divide by 37: $135 \div 37 = \frac{135}{37}$ (approx. 3.65)
Answer: $\frac{135}{37}$ or approximately $3.65$
&vi. Calculate $\left[7 + 3(23 - 1)\right] \div 21$
Calculate inside parentheses: $23 - 1 = 22$
Multiply: $3 \times 22 = 66$
Inside brackets: $7 + 66 = 73$
Divide by 21: $73 \div 21 = \frac{73}{21}$ (approx. 3.48)
Answer: $\frac{73}{21}$ or approximately $3.48$
2) Solve the following equations:
i. Solve $2(3x - 4) = 4x + 10$
Expand left side: $6x - 8 = 4x + 10$
Subtract $4x$ from both sides: $6x - 4x - 8 = 10$
Simplify: $2x - 8 = 10$
Add 8 to both sides: $2x = 18$
Divide both sides by 2: $x = 9$
Answer: $x = 9$
ii. Solve $|3x + 5| = 17$
Two cases:
Case 1: $3x + 5 = 17$
Subtract 5: $3x = 12$
Divide by 3: $x = 4$
Case 2: $3x + 5 = -17$
Subtract 5: $3x = -22$
Divide by 3: $x = -\frac{22}{3}$
Answer: $x = 4$ or $x = -\frac{22}{3}$
iii. Solve $|x + 5| = -8$
Absolute value cannot be negative
No solution
Answer: No solution
iv. Solve $|2x + 5| = x - 1$
Right side must be nonnegative: $x - 1 \geq 0 \Rightarrow x \geq 1$
Case 1: $2x + 5 = x - 1$
Subtract $x$: $x + 5 = -1$
Subtract 5: $x = -6$
Not valid since $x \geq 1$, discard
Case 2: $-(2x + 5) = x - 1$
$-2x - 5 = x - 1$
Add $2x$: $-5 = 3x - 1$
Add 1: $-4 = 3x$
Divide by 3: $x = -\frac{4}{3}$
Not valid since $x \geq 1$, discard
Answer: No solution
v. Solve $|3x - 2| = 0$
Absolute value equals zero means inside is zero
$3x - 2 = 0$
$3x = 2$
$x = \frac{2}{3}$
Answer: $x = \frac{2}{3}$
3) Solve each inequality:
1. $6 < x + 3 < 8$
Subtract 3: $3 < x < 5$
Answer: $x \in (3,5)$
2. $7 < x + 5 < 11$
Subtract 5: $2 < x < 6$
Answer: $x \in (2,6)$
3. $|2x - 6| > 8$
Two cases:
$2x - 6 > 8 \Rightarrow 2x > 14 \Rightarrow x > 7$
Or
$2x - 6 < -8 \Rightarrow 2x < -2 \Rightarrow x < -1$
Answer: $x < -1$ or $x > 7$
4. $|3x + 5| < 17$
Inside absolute value between $-17$ and $17$
$-17 < 3x + 5 < 17$
Subtract 5: $-22 < 3x < 12$
Divide 3: $-\frac{22}{3} < x < 4$
Answer: $x \in \left(-\frac{22}{3}, 4\right)$
5. $|2(x - 1) + 4| \leq 8$
Inside absolute value: $2x - 2 + 4 = 2x + 2$
Inequality: $|2x + 2| \leq 8$
So, $-8 \leq 2x + 2 \leq 8$
Subtract 2: $-10 \leq 2x \leq 6$
Divide 2: $-5 \leq x \leq 3$
Answer: $x \in [-5, 3]$
6. $|4x + 8| < 0$
Absolute value cannot be negative
No solution
Answer: No solution
7. $|x + 1| \geq 0$
Absolute value always nonnegative, so true for all $x$
Answer: $x \in \mathbb{R}$ (all real numbers)
8. $1 - (x + 3) \geq 4 - 2x$
Simplify left: $1 - x - 3 = -x - 2$
Inequality: $-x - 2 \geq 4 - 2x$
Add $2x$: $x - 2 \geq 4$
Add 2: $x \geq 6$
Answer: $x \geq 6$
9. $5(3 - x) \leq 3x - 1$
Expand left: $15 - 5x \leq 3x - 1$
Add $5x$: $15 \leq 8x -1$
Add 1: $16 \leq 8x$
Divide by 8: $2 \leq x$
Answer: $x \geq 2$