If x=-1 , y=1 and z =2 then find the value of. a . 2x+3y +4z b. 5x2 +3y2+7z2​

a.2×1= 2 + 3×1=3 +4×2=8 now we have to put this ans and the ans is 13.

b. 5×1×2=10 + 3×1×2=6+ 7×2×2=28 now also we have to put this ans and this ans is 13

the difference of two squares is a special form that has a factorization worth memorizing.

a² - b² = (a - b)(a + b)

your equation can be factored as

x² - 16 = 0

(x - 4)(x + 4) = 0

the zero product rule tells you the solutions are the values of x that make these factors zero: x=4, x=-4.