Mathematics: Find the zero of y=4x^2-12x-16

Find the zero of y=4x^2-12x-16 - id4212164577876, zstarr

Ответ:

tyresharichardson29

15.01.2022

$\large\boxed{x=-1\ or\ x=4}$

Step-by-step explanation:

$y=4x^2-12x-16\\\\\text{the zeros are for}\ y=0:\\\\4x^2-12x-16=0\qquad\text{divide both sides by 4}\\\\x^2-3x-4=0\\\\x^2+x-4x-4=0\\\\x(x+1)-4(x+1)=0\\\\(x+1)(x-4)=0\iff x+1=0\ \vee\ x-4=0\\\\x+1=0\qquad\text{subtract 1 from both sides}\\\boxed{x=-1}\\\\x-4=0\qquad\text{add 4 to both sides}\\\boxed{x=4}$