<u>Answer:</u>
96
<u>Step-by-step explanation:</u>
Let's assume that the marks needed in the next exam is
. Then if the average becomes 90,

Now we can simply solve for
:
⇒ 
⇒
[Multiplying both sides by 4]
⇒
[Subtracting 264 from both sides]
⇒ 
Therefore, you need to score 96 in your next exam to have an average of 90 on the four exams.
Multiply the top equation by 6 and the bottom equation by 7. You will cancel x first by doing this and solve for y. You should get y=-1.
Substitute in y for either original equation.
You should get x=1.
Solution is (1,-1).
Answer:
3x<u>></u><u>=</u><u> </u><u>21</u>
Step-by-step explanation:
Happy 2 Help. Hope you get a good grade lol
Answer:
x^2-4x-12
Step-by-step explanation:
(x-6)(x+2)=x^2-6x+2x-12=x^2-4x-12