Question

solve using the substitution method.
11x + 10y = 77 9x + y = 63

Answer 1

\[\begin{cases}11x+10y=77\\9x+y=63\end{cases}\]
\[\begin{cases}11x+10(63-9x)=77\\y=63-9x\end{cases}\]
now find x in first equation and plug it into second

Answer 2

make one of the variables the same lets make y the same value so

9x + y = 63 (multiply by 10)

90x + 10y = 630
11x + 10y = 77

79x = 553

x = 7

now we know the value of x we use it to work out the value of y

Answer 3

so 11(7) + 10y = 77

77 + 10y = 77

10y = 77 - 77

10y = 0

10y / 10 = 0 / 10

y = 0

lol

Answer 4

@lilg132 I think it's not substitution method or it is?

Answer 5

elimination sorry

Answer 6

let me do it again using substitution

Answer 7

I have done most of it, now you need just to find x and y and he should be able to do it himself

Answer 8

11x + 10y = 77
9x + y = 63

y = 63 - 9x

so we use this in the first equation

11x + 10(63 - 9x) = 77

11x + 630 - 90x = 77

11x - 90x = 77 - 630

-79x = -553

-x = -7

x = 7

use this to work out y in the second equation

Answer 9

9(7) + y = 63

63 + y = 63

y = 63 - 63

y = 0