Problem:
Solve 10x+5y=72;15x+4y=80
Steps:
I will try to solve your system of equations.
10x+5y=72;15x+4y=80
Step: Solve10x+5y=72for x:
10x+5y+−5y=72+−5y(Add -5y to both sides)
10x=−5y+72
10x
10
=
−5y+72
10
(Divide both sides by 10)
x=
−1/2 y+36 5
Step: Substitute
−1
2
y+
36
5
forxin15x+4y=80:
15x+4y=80
15(
−1
2
y+
36
5
)+4y=80
−7
2
y+108=80(Simplify both sides of the equation)
−7
2
y+108+−108=80+−108(Add -108 to both sides)
−7
2
y=−28
−7
2
y
−7
2
=
−28
−7
2
(Divide both sides by (-7)/2)
y=8
Step: Substitute8foryinx=
−1
2
y+
36
5
:
x=
−1
2
y+
36
5
x=
−1
2
(8)+
36
5
x=
16
5
(Simplify both sides of the equation)
Answer:
x=16/5
and y=8
