Three times the sum of 4 and a number y squared is the same as the difference of 14and the number y

Question

Three times the sum of 4 and a number y squared is  the same as the difference of 14and the number y

anonymous · Answer

Simplify

anonymous · Answer

can you answer it

anonymous · Answer

Yep - give me a sec :)

anonymous · Answer

$$[3(4+y)]^2 = 14-y$$
$$(12+3y)^2 = 14-y$$
(12+3y)(12+3y) = 14-y

144 + 36y + 36y + 9y^2 = 14 - y

anonymous · Answer

You then group the like terms, and solve the quadratic (I'll give you a second to try, while I'm writing out the rest)

anonymous · Answer

130 + 73y + 9y^2 = 0

anonymous · Answer

Have you been taught to use the quadratic equation to solve these kinds of questions?

anonymous · Answer

i read it as 
3(4+y^2)=14-y 
12+3y^2=14-y 
3y^2+y+12-14=0 
3y^2+y-2=0

anonymous · Answer

Ah OK! Then you are correct in your working out :) It depends on the punctuation in the question :)

anonymous · Answer

(The answers for y are y = 2/3 , or y = -1, by the way :) )