Question

(1) Find the sum of a² - 7a + 10 and 3a²+ 4a - 15.

(2) Find the value of x² + 2 at x = 2 & x = -1

(3) Express given number using power notation
(a) 81/100
(b) 27/125

(4) Evalute
(a) (-3)³ (b) (-5)⁴

(5) Find the Area of the circle whose radius is 14 cm.
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Answer 1

$\sf\huge\bold{\underline{\underline{{Solution}}}}$

(1) a²-7a+10 and 3a²+4a-15

➙a²-7a+10 +3a²+4a-15

Arranging the terms and making like terms

➙a²+3a²-7a+4a+10-15

➙4a²-7a+4a+10-15

➙4a²-3a+10-15

➙4a²-3a-5

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(2) x²+2

At x =2

➙(2)²+2

➙4+2=6

At x= -1

➙(-1)²+2

➙1+2=3

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(3)

a) 81/100= 3⁴/10²= (3²/10)²

b) 27/125= 3³/5³= (3/5)³

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4)

a) (-3)³

since ,power is odd so, resultant would be negative

➙ -3×-3×-3= 9×-3= -27

b)(-5)⁴

since ,power is even so, resultant would be positive

(-5)⁴= -5×-5×-5×-5= 25× -5×-5= 25×25= 625 or (25)²

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5) Radius = 14cm

Area of circle = πr²

Area of circle = 22/7× (14)²

Area of circle = 22/7 × 196

Area of circle = 22×28=616

Area of circle = 616cm²