Question

What is the solution of the system ??
4x+3y= 12
7x+5y=26
a.(18,20)
b.(18,-20)
c.(-20,18)
d.(20,18)
is it c?

Answer 1

to eliminate y, multiply the first equation by 5 and the second equation by 3:

20 x + 15 y = 60
21 x + 15 y = 78
--------------------subtract
-1 x = - 18
so
x = 18
so
4(18) + 3 y = 12
72 + 3 y = 12
3 y = -60
y = -20
-----------------------
check that to be sure
7(18) + 5 (-20) = ???? 26
126 - 100 = 26 sure enough it checks

Answer 2

so its b @damon?

Answer 3

Yes, but no need to ask is there?

Answer 4

nope. you helped alot.

Answer 5

@damon can you help me with this one ?

What is the solution of the system? use substitution . 4x+2y=10, y=-3x+6

My answer chosies are
a. (1,-3)
b.(1,3)
c.(3/10, 4/5)
d.(-2,-2)

Answer 6

is it b? @damon

Answer 7

Henry and I have both done this already, scroll down.

Answer 8

http://www.jiskha.com/display.cgi?id=1452020437

Start trying to do them and stop asking us to do it all.

Answer 9

yall have helped alot .