Answers

2016-07-27T08:51:06+08:00
I think it should be ax^2 + bx + c = 0

1. x(x+5)=2
= x^2 + 5x = 2
= x^2 + 5x -2 = 0
2. (s+6)^2 = 15
= s^2 + 12x + 36 = 15
= s^2 + 12x + 36 - 15 = 0
= s^2 + 12x + 21 = 0
3. (t + 2)^2 + (r + 4)^2 = 10
= (t^2 + 4x + 4) + (r^2 + 8r + 16) = 10
= t^2 + r^2 + 4t + 8r +4 + 16 - 10 = 0
= t^2 + r^2 + 4t + 8r + 10 = 0

You cannot combine t^2 & r^2, and 4t & 8r because they are not like terms.

I think you typed #3 incorrectly. If ever the problem in #3 is (t + 2)^2 + (t + 4)^2 = 10 , the answer will be 2t^2 + 4t + 10.
0
Corrections: In number 2, it should be 12s, not 12x. And in number 3, it should be 4t, not 4x.
Another correction: if ever the question is (t+2)^2 + (t+4)^2 = 10 the answer would be 2t^2 + 12t - 10 = 0 (not 4t)
* + 10