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42 votes
42 votes
Which value of x makes the equation 3.5(x+20)=6+.75(x+1) true?

User Wudizhuo
by
2.8k points

2 Answers

18 votes
18 votes

Answer:

x = -23

Explanation:

3.5(x+20) = 6 + .75(x + 1) Multiply the terms inside the parentheses on the left by 3.5 and the parentheses on the left by .75

(3.5)x +(3.5)(20) = 6 + (.75)x +(.75)(1)

3.5x + 70 = 6 + .75x + .75 Combine the 6 and .75 on the right side

3.5x + 70 = 6.75 + .75x Subtract .75x from both sides of the equation

2.75x + 70 = 6.75 Subtract 70 from both sides of the equation

2.75x = -63.25 Divide both sides by 2.75

x = -23

Check

3.5(-23+20) = 6 + .75(-23 + 1)

3.5(-3) = 6 +.75(-22)

-10.5 = 6 +(-16.5)

-10.5 = -10.5

User Whitefox
by
3.3k points
7 votes
7 votes

Answer:

x = -23

Explanation:

3.5(x+20)=6+.75(x+1)

3.5x + 70 = 6 + .75x + .75

3.5x+70=.75x+6.75

2.75x+70=6.75

2.75=−63.25

divide^

x = -23

User David McLaughlin
by
3.1k points