Question

Solve:

4a+2c=70
8a+12c=196
Use the elimination method or substitution method to solve
Enjoy :)

Answer 1

♥ First lets find the value of a
Steps we can use:

`4a + 2c = 70`

`4a = 70 - 2c`

`(4a)/(4) = ((70 - 2c))/(4)`

`a = ((70 - 2c))/(4)`

♥Now we are going to substitute for the value of a...

`8a + 12 c = 196`

`8 ((70 - 2c)/4) + 12c = 196`

`(8*70)/4 - (8*2c)/4) + 12c = 196`

`(560 / 4) - (16c / 4) + 12c = 196`

`140 - 4c + 12c = 196`

`-4c + 12c = 196 - 140`

`8c = 56`

`8c / 8 = 56 / 8`

`c = 7`

Now moving onto A:


`(70 - 2c) / 4`

`a = ((70 - 2(7))/4`

`a = (70 - 14)/4`

`a = 56 / 4`

`a = 14`

Thus, if you follow these rules, you can solve:
c=7 a=14

Answer 2

4a + 2c = 70 ; a = 14 ; c = 7 ; 4(14) + 2(7) = 70 ; 56 + 14 = 70 ; 70 = 70
8a + 12c = 196 ; 8(14) + 12 (7) = 196 ; 112 + 84 = 196 ; 196 = 196

Get the value of a:

4a + 2c = 70
4a = 70 - 2c
4a/4 = (70 - 2c) / 4
a = (70 - 2c) / 4

Substitute the value of a:

8a + 12 c = 196
8 ((70 - 2c)/4) + 12c = 196
(8*70)/4 - (8*2c)/4) + 12c = 196
(560 / 4) - (16c / 4) + 12c = 196
140 - 4c + 12c = 196
-4c + 12c = 196 - 140
8c = 56
8c / 8 = 56 / 8
c = 7

a = (70 - 2c) / 4
a = ((70 - 2(7))/4
a = (70 - 14)/4
a = 56 / 4
a = 14