Question

solve the eqation
x+3y=45
2x+y=45

Answer 1

solve for x in the first equation ...
\[\large{x+3y=45}\]
\[\large{x=45-3y}\]

put this in the second equation at the place of x

Answer 2

Substitution...
Solve for x in the first equation:
x + 3y = 45
x = -3y + 45
Substitute the value of x into the second equation to solve:
2x+y=45
2(-3y + 45) +y=45
Can you solve from there?

Answer 3

\[\large{2x+y=45}\]
\[\large{2(45-3y)+y=45}\]
\[\large{2(45)-2(3y)+y=45}\]
\[\large{90-6y+y=45}\]
\[\large{90-5y=45}\]

Answer 4

\[\large{5y=90-45}\]

Answer 5

ummm @mathslover are you giving me the final answer that i need to do the last step on??

Answer 6

Did i proceed to the final answer?

Answer 7

what do you want? :

a) answer
b) solution ... (explained) ?
c) none

Answer 8

a and b

Answer 9

ok so can you solve :

90 - 5y = 45 ????????

Answer 10

yeah

Answer 11

what's the answer then ?

Answer 12

9

Answer 13

is that right??? @mathslover

Answer 14

@jazy am i right?

Answer 15

Right! (:

Answer 16

okay then what do i do next?

Answer 17

Well you just solved for y. y = 9
You need to find the value of x. To do that, just put the y-value into any one of the equations and solve for x.
\[x+3y=45 \]\[x+3(9)=45\]\[x+27=45\]\[Solve for X\]

Answer 18

so i have to subtract 27 on both sides.. when i did that i got 18

Answer 19

Good (:
So now you know that
x = 18
y = 9

Answer 20

ohhhhh okay thanks :))

Answer 21

welcome. (: