Question

Q13. Evaluate :
(a) xyz - 3yz - 2xy if x=2, y=3, z=0
(b) 4a - 5b + c if a = 2.b = -1,c= 1​

Answer 1

Answer :-

1) -12

2) 14

Given -

• xyz - 3yz -2xy where x = 2, y = 3 and z = 0

• 4a - 5b + c where a = 2 , b = -1 and c = 1

To -

• Evaluate the above expression.

Solution -

In 1st case -

→ (0)(3)(2) - 3(3)(0) - 2(2)(3)

→ 0 - 0 - 12

→ -12 Ans

In 2nd case -

→ 4(2) - 5(-1) + (1)

→ 8 - (-5) + 1

→ 14 Ans

Procedure -

• This question is from the polynomials.

• In this question we are given with 2 expression and value of x,y & z + the values of a,b & c is also given.

• In this we will be puting the values 2 in place of x, 3 in place of y and 0 in place of z in first case and 2 in place of a, -1 in place of b and 1 in place of c in second case.

• After placing the numerical values in place of variable value we will equate the whole expression and will bring out the final answer.

$\therefore$ In 1st case = -12 is the answer 2nd case 14 is the answer.

Remember !!

• (+)(-) = -

• (-)(+) = -

• (+)(+) = +

• (-)(-) = +

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Answer 2

Answer:

a)-12 b)14

Step-by-step explanation:

a)xyz-3yz-2xy

=y(xz-3z-2x)

=3(2x0 - 3x0 - 2x2)

=3(0-0-4)

=3 x -4

=-12

b)4a-5b+c

=4x2 - 5x(-1) + 1

=8-(-5)+1

=8+5+1

=14

Hope you understood the answer. :)