Question

Need help with these please???

Answer 1

Solution :

a. 36 - 20 = 16 units

According to basic proportionality theorem ,

• $\sf\implies\::\dfrac{30}{x\:+\:5}\:=\:\dfrac{16}{20}$

• Cross multiply
• ( x + 5 ) × 16 = 30 × 20
• 16x + 80 = 600
• 16x = 600 - 80
• 16x = 520
• $\sf\implies\::x\:=\:\dfrac{520}{16}$
• x = 32.5

Value of x + 5

• 32.5 + 5
• 37.5 units

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b. By using basic proportionality theorem ,

• $\sf\implies\::\dfrac{4}{2x\:+\:4}\:=\:\dfrac{3}{x\:+\:7}$

• Cross multiply
• ( x + 7 ) × 4 = 3 × ( 2x + 4 )
• 4x + 28 = 6x + 12
• 28 - 12 = 6x - 4x
• 16 = 2x
• $\sf\implies\::\dfrac{16}{2}\:=\:x$
• x = 8

Value of x + 7

• 8 + 7
• 15 units

Value of 2x + 4

• 16 + 4
• 20 units