Question

pls tell the answer of these two​

Answer 1

1). Question :

Factorize the following :

a). y² - 14y + 49

=> y² - 14y + 49

=> y² - 2•y•7 + 7²

=> (y - 7)²

=> (y - 7)(y - 7)

b). x² + 3x - 40

=> x² + 3x - 40

=> x² + 8x - 5x - 40

=> x(x + 8) - 5(x + 40)

=> (x + 8)(x - 5)

2). Question :

Find the height of trapezium , the sum of lengths of whose parallel sides is 60 cm and whose area is 600 cm² .

Note :

• If a and b are the lengths of parallel sides and h is the height of trapezium , then the area of the trapezium is given by A = (a + b)•h

Solution :

• Given : Sum of parallel sides of trapezium , (a+b) = 60 cm , Area of trapezium , A = 600 cm²
• To find : Height of trapezium , h = ?

We have ;

=> A = 600

=> (a + b)•h = 600

=> 60h = 600

=> h = 600/60

=> h = 10

Hence ,

The height of the trapezium is 10 cm .

Answer 2

$a. {y}^{2} - 14y + 49 \\ \longmapsto {y}^{2} - 14y + 49 \\ \longmapsto \: {y}^{2} - 2 \: y \: 7 + {7}^{2} \\ \longmapsto \: (y - {7})^{2} \\ \longmapsto \: (y - 7)(y - 7) \\ \\ \\ b. {x}^{2} + 3x - 40 \\ \longmapsto \: {x}^{2} + 3x - 40 \\ \longmapsto \: {x}^{2} + 8x - 5x - 40\\ \longmapsto \: x(x + 8)( x - 5) \\ \longmapsto \: a = 600 \\ \longmapsto(a + b)h = 600 \\ \longmapsto60h = 600 \\ \longmapsto \: h = 600 \div 60 \\ \longmapsto \tt \: h = 10$