Question

What is a correct first step in solving the inequality –4(3 – 5x)≥ –6x + 9? –12 – 20x ≤ –6x + 9 –12 – 20x ≥ –6x + 9 –12 + 20x ≤ –6x + 9 –12 + 20x ≥ –6x + 9

Answer 1

Question : what is correct step in solving the inequality , -4(3 - 5x) ≥ -6x + 9

(a) –12 – 20x ≤ –6x + 9

(b) –12 – 20x ≥ –6x + 9

(c) –12 + 20x ≤ –6x + 9

(d) –12 + 20x ≥ –6x + 9

Solution : inequality follow algebraic addition, subtraction and multiplication but it has also own some kind of rules.

i. If a > b ⇒-a < - b

ii. a/b > c ⇒a > bc if b > 0

iii. a/b > c ⇒a < bc if b < 0 And many more.

now here we have, -4(3 - 5x) > -6x + 9

⇒-4 × 3 - (-4) × 5x > -6x + 9

⇒-12 + 20x > -6x + 9

Therefore option (c) is correct step to solve the inequality.

[ Note : -12 + 20x > - 6x + 9

⇒20x + 6x > 9 + 12

⇒26x > 21

⇒x > 21/26

so solution of inequality is x > 21/26 ]