311(1.50)+.50x=385.50
would be your equation
I think it would be 12.207… use the Pythagorean theorem (a^2+b^2=c^2) so 10^2+7^2
100+49=149
Then take square root of 149 to undo the the squaring of c and it should be around 12.207 :)
Perform the indicated multiplications...
12x*x+12x*2-5*2x-5*(-1)
12x^2+24x-10x+5 combine like terms
12x^2+14x+5
