Advertisements
Advertisements
प्रश्न
Multiply and then evaluate:
(4x + y) and (x – 2y); when x = 2 and y = 1.
Advertisements
उत्तर
(4x + y) × (x − 2y)
= 4x (x − 2y) + y (x − 2y)
= 4x2 − 8xy + xy − 2y2
= 4x2 − 7xy − 2y2
Verification:
When x = 2, y = 1
L.H.S. = (4x + y) (x − 2y)
= (4 × 2 + 1) (2 − 2 × 1)
= (8 + 1) (2 − 2)
= 9 × 0
= 0
R.H.S. = 4x2 − 7xy − 2y2
= 4 (2)2 − 7 × 2 × 1 − 2 (1)2
= 4 × 4 − 14 − 2
= 16 − 16
= 0
∴ L.H.S. = R.H.S.
संबंधित प्रश्न
Find the value of `"yx"/"z"`, when x = 8, y = 4 and z = 16
If a = 3, b = 0, c = 2 and d = 1, find the value of a2 + 2b2 − 3c2
If x = 2, y = 5 and z = 4, find the value of the following:
zx
Simplify:
3x + (8x − 5x) − (7x − x)
Simplify:
`"a"-(2"a"-overline(4"a"+3"a"))`
Fill in the blank:
2a + b − c = 2a + (.............)
Fill in the blank:
a + b − c + d = a + (...............)
Insert the bracket as indicated:
ab + 2bc − 3ac = 2bc − (...............)
If x = 2, y = 3 and z = 4, find the value of 3x2 – 4y2 + 2z2.
Simplify:
5 (x + 3y) – 2 (3x – 4y)
