Q1:  Find the intersection of 2P=4Q-10 and P= -Q+10.

A1:  Dividing both sides of the first equation by 2 we find that P=2Q-5.  Since at the intersection the P is the same for both equations we can set 2Q-5=-Q+10, which is 3Q=15 or Q=5.  Plugging this back into either of the two original equations we find that 5=-Q+10 or -Q=-5 or Q=5.

Q2:  Calculate ¶/¶y  x³y²+7xy³+3x+4y+7

A2:   2x³y+21xy²+4