Question

1.twice a number when decreased by 9 gives 43.

2.thrice a number when increased by 5 gives 38.

3.four added to twice a number yields 26/5.

4 a number when added to its half gives 72

Answer 1

Step-by-step explanation:

1. Let the number be x.

Twice the number is equal to 2x

Decreased by 9 is equal to 2x-9.

According to the question 2x-9 =43.

2x=9+43

2x=52

x=52÷2

x=26.

Therefore the number is 26.

2.Let the number be x

Thrice the number is equal to 3x

Increased by 5 is equal to 3x+5

According to the question 3x +5=38

3x =38-5

3x =33

x=33÷3

x=11

Therefore the number is 11

3.Let the number be x

Twice a number is equal to 2x

Four added to the number is equal to 2x +4

According to the question 2x+4=26/5

2x =26/5 - 4

2x = 26-20/5

2x =6/5

2x ×5=6

10x=6

x=6/10

x=3/5

Therefore the number is 3/5.

4.Let the number be x

Half the number is equal to x/2

According to the question x+x/2 =72

2x+x=72

3x = 72

x=72/3

x = 24

Therefore the number is 24