Factorise 16x2 + 4y2 + 9z2 – 16xy + 12yz – 24zx using standard algebraic identities.​

Step-by-step explanation:

16x2 + 4y2 + 9z2 – 16xy + 12yz – 24zx

(-4x)²+(2y)²+(3z)²+2(-4x)(2y)+2(2y)(3z)+2(-4x)(3z)

So,

(-4x+2y+3z)²

or

(-4x+2y+3z).(-4x+2y+3z)

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15