Question

Simplify (4x − 5)^2.

Answer 1

(a+b)^2=a^2 + b^2 + 2ab

Answer 2

does that mean "multiply"? start with
\[(4x+5)(4x+5)\] and do four multiplications

Answer 3

(a-b)^2 = a^2 + b^2 -2ab

Answer 4

oops rather
\[(4x-5)(4x-5)\]

Answer 5

thankss(:

Answer 6

do four multiplications, combine like terms, and then tell your teacher (gently) that there is nothing "simpler" about your result than there is in \((4x-5)^2\)

Answer 7

is it 16x+25?

Answer 8

oh no! careful here

Answer 9

four multiplications i will write them out

Answer 10

\[(4x-5)(4x-5)=4x\times 4x-5\times 4x-5\times 4x+5\times 5\]

Answer 11

(4x-5)^2 = 16x^2 -40x +25.

Answer 12

16x-40x+25?

Answer 13

then \(4x\times 4x=16x^2\)
\(-5\times 4x-5\times 4x=-20x-20x=-40x\)
\((-5)\times (-5)=25\) final answer is
\[16x^2-40x+25\]

Answer 14

now factorize it or solve by formula \[x=-b \pm \sqrt{b^{2}-4ac}/2a\]

Answer 15

no marmar it's 16x^2 - 40x +25.
not 16x

Answer 16

now use quadratic formula or apply factorization method.it's up to u

Answer 17

U got it marmar? just use formula (a-b)^2 = a^2 + b^2 -2ab.
then find x by factorization or quadratic formula.Simple!

Answer 18

yea, thanks guys!