2007-01-17 16:36:24 · 16 answers · asked by Christ' Soldier 2 in Science & Mathematics ➔ Mathematics
21x + 28 = 16x + 40 + 13
21x-16x=40+13-28
5x=25
x=5
2007-01-17 16:45:08 · answer #1 · answered by tingerpoo 2 · 1⤊ 0⤋
7(3x+4)=8(2x+5)+13
21x + 28 = 16x + 40 + 13
21x - 16x = 40 + 13 - 28
5x = 53 - 28
5x = 25
x = 25/5
= 5
2007-01-17 16:46:27 · answer #2 · answered by loally 2 · 2⤊ 0⤋
7(3x+4)=8(2x+5)+13 distribute 7 & 8
21x+28=16x+40+13 subtract 16x+28 from each side
5x=25 divide both sides by 5
x=5
2007-01-17 17:28:08 · answer #3 · answered by yupchagee 7 · 1⤊ 0⤋
7(3x+4)=8(2x+5)+13 Solve for x?
21x+ 28 = 16x+53
21x-16x=53-28
5X=25
X=25/5=5
X=5
2007-01-17 16:50:54 · answer #4 · answered by Jamie T 3 · 1⤊ 0⤋
7(3x+4)=8(2x+5)+13
(7 * 3x) + (7 * 4) = (8 * 2x) + (8 * 5) + 13
21x + 28 = 16x + 40 + 13
21x - 16x = 53 - 28
5x = 25
x = 5
DONE
2007-01-17 17:30:51 · answer #5 · answered by John Locke 2 · 1⤊ 0⤋
you have to get down to x on one side like this
7(3x+4=8(2x+5)+13
first step get rid of the bracets
21x+28=16x+40+13
now you get all the numbers on one side start by doing the math function asked for to get numbers to gether on one side
21x+28-28=16x+53-28 you need to add the 40=13 then subtract the 28because you are bringing it over from the otherside
this leaves you with this
21x=16x+25 now get all the x's on the same side do this by subtracting both sides by 16x
21x-16x=16x-16x+25 which gives you the following
5x=25 now divide both sides by the 5 so that the x is left on one side by itself
5x/5=25/5
x=5 is your answer
you can check your answer by putting 5 in the place of the x's in the original problem
2007-01-17 16:56:49 · answer #6 · answered by emmandal 4 · 1⤊ 0⤋
Use distributive property:
21x+28=16x+40+13
21x+28=16x+53
Subtract 16x from both sides:
5x+28=53
Subtract 28 from both sides:
5x=25
Divide 5 from both sides:
x=5
Check:
7(3(5)+4)=8(2(5)+5)+13
7(15+4)=8(15)+13
7(19)=120+13
133=133
2007-01-17 17:40:01 · answer #7 · answered by Anonymous · 0⤊ 0⤋
remember pemdas? parenthesis, exponents, mult, divi, add, sub. simplify= parentheses mean mult= 21x + 28= 16x +40 +13. 21x +28= 16x +53 now subtract the 16x from 21x. 5x+28= 53 then sub 28 from 53. 5x=25. divide both sides by 5 to get x all alone. x=5.
2007-01-17 16:47:52 · answer #8 · answered by xNENA . 1 · 1⤊ 0⤋
expand and simplify:
21x + 28 = 16x + 40 +13
21x - 16x = 53 - 28
5x = 25
x = 5
2007-01-17 16:44:41 · answer #9 · answered by Anonymous · 2⤊ 0⤋
7(3x+4)=8(2x+5)+13
21x+28=16x+40+13
5x=25
x=5
2007-01-17 16:45:39 · answer #10 · answered by Anonymous · 1⤊ 0⤋