Answer:
143
Step-by-step explanation:
lets make a fraction:
so
91 oil changes/7days
lets take "x" as the unknown # of oil changes:
so
x/11
91/7=x/11
we can cross multiply:
91*11=7*x
1001=7x
143=x
so 143 oil changes in 11 days
Hope this helps!
D) 36x^2-81
both 36x^2 and -81 are perfect squares
difference means subtraction
3x^2 - 12 = 0
Personally, I would divide each side by 3 x^2 - 4 = 0
Then I would add 4 to each side x^2 = 4
Then I would take the square root of each side: x = +4
x = -4 .
Having found both solutions, I would relax with a cup of tea.
Golden retrievers: 12/32
poodles: 20/32
does it need to be simplified?
Answer:
(82/3, -111/2) or x=82/3, y=-111/2
Step-by-step explanation:
