Algebraic Expressions & Identities Test

Result

Algebraic Expressions & Identities Test - 4

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

If 2m - 9n = 12 and mn = -2, then the value of 4m² + 81n² is

A
72

B
75

C
82

D
84

Solution

We have 2m - 9n = 12 and mn = -2
Squaring both sides,

(2m - 9n)² = (12)²
(2m)² + (9n)² - 36mn = 144

4m² + 81n² - 36 x (-2) = 144
4m² + 81n² + 72 = 144
4m² + 81n² = 144 - 72 = 72
Question 2
1 / -0

What must be added to 16y²- 4y + 8 to get 6y² - 2y - 4?

A
-10y² + 2y - 12

B
-10y² + 4y - 12

C
-10y² + 4y + 4

D
10y² - 2y + 44

Solution

Let the term added be 'a'.
16y²- 4y + 8 + a = 6y²- 2y - 4

⇒ a = 6y²- 2y - 4 - (16y²- 4y + 8)
⇒ a = 6y²- 2y - 4 - 16y²+4y - 8
⇒ a = -10y²+ 2y - 12