How do you solve \frac { 3} { 6} ( 4x - 8) = 7x - 25?

2 Answers
Jan 30, 2018

x=21/5

Explanation:

"simplify and distribute the bracket on the left side"

rArr1/2(4x-8)=7x-25

rArr2x-4=7x-25

"subtract 7x from both sides"

2x-7x-4=cancel(7x)cancel(-7x)-25

rArr-5x-4=-25

"add 4 to both sides"

-5xcancel(-4)cancel(+4)=-25+4

rArr-5x=-21

"divide both sides by"-5

(cancel(-5) x)/cancel(-5)=(-21)/(-5)

rArrx=21/5

color(blue)"As a check"

Substitute this value into the equation and if both sides are equal then it is the solution.

"left "=1/2(84/5-40/5)=1/2xx44/5=22/5

"right "=147/5-125/5=22/5

rArrx=21/5" is the solution"

Jan 30, 2018

21/5 = 4 1/5

Explanation:

3/6(4x-8)=7x-25

or, 3/6 xx4x-3/6 xx8 = 7x-25

or, cancel3^1/cancel6^2 xx4x -3/cancel6^3 xxcancel8^4 = 7x-25

or, 1/cancel2^1 xxcancel4^2x-cancel3^1/cancel3^1 xx4 = 7x-25

or, 2x-4=7x-25

Bring the x terms to one side and number terms to other side of equal to sign.

or, 2x-7x=-25+4 (bringing any term from one side of equal to sign to other side causes the sign/mathematical operator to change it to its opposite sign. Which is + becomes - and xx becomes / or vice -versa.

or, -5x = -21

or x = -21/-5 = 21/5 (the negative signs in the numerator and denominator get cancelled out)

or, x = 21/5 = 4 1/5