express 4x squared + 2x -3 in the form of (2x+a)^2 -b ,
so i factorised the 2 out and i got 2(2x^2 + x) -3 , then i halfed the second coefficient and got 2( 2x+ 1/2) ^2 - 3.25
ok for that question i thought i could use the same method for this question, express 4x^2 + 8x- 21 in the form of a(x+p)^2 + q , i factorised the 4 and got 4( x^2+2x) -21, halved the second coffiecent and got 4(x^2 + 1)^2 -21 -1 , which is 4(x +1) ^2 -22, but that's wrong!! I don't kno how tho