SOLUTION: Solve the system by substitution. 2x + 4y = 10 y = 2x + 15

Algebra.Com
Question 28155: Solve the system by substitution.
2x + 4y = 10
y = 2x + 15

Answer by sdmmadam@yahoo.com(530)   (Show Source): You can put this solution on YOUR website!
Solve the system by substitution.
2x + 4y = 10 ----(1)
y = 2x + 15 ----(2)
Putting (2) in (1) (that is substituting for y)
Then (1) becomes
2x + 4(2x+15) = 10
2x +(8x +60) = 10
(2x+8x) =10-60 [By additive associativity and adding (-60) to both the sides]
10x = -50
x = (-50)/10 = -5
Putting x=-5 in (2),
y = 2x +15 becomes
y = 2X(-5) +15 = -10 + 15 = +5
Answer: x = -5 and y = 5
Verification: putting x = -5 and y = 5 in (1)
LHS = 2x + 4y = 2X(-5)+ 4X(5) = -10+20 = 10 =RHS
Therefore our answer is correct.

RELATED QUESTIONS

Solve the system by substitution. x + y = 12 y = 2x Solve the system by addition (answered by jim_thompson5910)
solve system by substitution 8x-4y=16... (answered by jim_thompson5910)
Solve the system by the method of substitution. 1/2x + 3/4y = 10 3/4x - y =... (answered by Alan3354)
Solve the system by using the substitution method. x-2y= 10, 2x-4y=... (answered by oberobic)
Solve the system of equations using substitution 3x + 4y=12 2x +... (answered by angelicnwa,mananth)
Solve the system by the substitution method. -2x + y = -2 x - 4y = 9 (answered by jim_thompson5910)
. Solve the following system by substitution. 8x – 4y = 16 y = 2x - 4 (answered by Cintchr)
solve the following system by substitution. 8x -4y=16 y=2x- 4 (answered by venugopalramana)
Solve the following system by substitution 8x-4y=16... (answered by jainenderkapoor)