Use substitution.
2p + 3(2p) = 680
2p + 6p = 680
8p = 680
p = 85
Plug in.
x = 2p
x = 2(85)
x = 170
p = 85
Remember
if ab=0, then assume that a and b equal 0
factor out common term
comon term in 6x^2 and 15x is 3x
3x(2x)+3x(5)=0
3x(2x+5)=0
set each to zero
3x=0
x=0
2x+5=0
2x=-5
x=-5/2
x=-5/2 and 0
Answer:
Step-by-step explanation:
t = tutoring and g = grocery store
t + g = 15......t = 15 - g
15t + 9g = 159
15(15 - g) + 9g = 159
225 - 15g + 9g = 159
-15g + 9g = 159 - 225
-6g = - 66
g = -66/-6
g = 11 <===== 11 hrs worked at the grocery store
t + g = 15
t + 11 = 15
t = 15 - 11
t = 4.....4 hrs tutoring
90 and 91...................
