96.2k views
5 votes
Find the value of the variable for which the value of the expression –3(2x+1) is 20 greater than the value of the expression 8x+5

2 Answers

2 votes

Answer:

X = -2

Explanation:

User Mohsen Ali
by
7.7k points
6 votes

Answer:

-2

Explanation:

20 greater than 8x +5 is ...

... 8x +5 +20 = 8x +25

We want this value to be -3(2x +1), so we want to solve the equation ...

... 8x +25 = -3(2x +1)

... 8x +25 = -6x -3 . . . . . . eliminate parentheses

... 14x = -28 . . . . . . . . . . . add 6x-25

... x = -2 . . . . . . . . . . . . . . divide by the coefficient of x

The desired value of the variable is -2.

_____

Check

-3(2x+1) = -3(2(-2)+1) = -3(-3) = 9

8x+5 = 8(-2) +5 = -11

9 is 20 greater than -11, so the answer checks OK.

User Lev Khruschev
by
8.2k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories