Question

Evaluate

1. Given that a= -2, b = 1 and c= 2
then Find
a). a²+b²+c²
b). 5/3 a²b + ¾ abc + 5
2. If x = -1, y=2 and z=-2 , evaluate
3x²y +5xy²+2xyz

Answer 1

1. Ans;

a). a²+b²+c² —> (-2)²+ (1)²+(2)²=4+1+4= 9

b).

`(5)/(3) {a}^(2) b + (3)/(4) abc + 5 \\ \\ (5)/(3) ( { - 2)}^(2) (1) + (3)/(4) ( - 2)(1)(2) \\ \\ (5)/(3) (4) + (3)/(4) ( - 4) \\ \\ = (20)/(3) - 3 \\ (20 - 9)/(3) = (11)/(3) = 3.666`

2. Ans;

3x²y+5xy²+2xyz = 3(-1)²(2) + 5(-1)(2)² + 2(-1)(2)(-2) = 3(1)(2) + 5(-1)(4) + 2(4) = 6 – 20 + 8 = – 6

I hope I helped you^_^