Question

assignment of 7 class​

Answer 1

Explanation:

1. a) 5x+3=13 for (x=2)

5×2+3=13

10+3=13

13=13

Right

b) 7y+3=17 for ( y=-3)

7×(-3)+3=17

-21+3=17

-18#17

Wrong

2. a) y-3=7

b) n÷5=9

Answer 2

Hey Pretty Stranger!

Answer 1 a)

$\sf \: 5x + 3 = 13$

When x = 2

$\sf \: 5(2) + 3 = 13$

$\sf \: 10+ 3 = 13$

$\sf \: 13 = 13$

$\therefore$ Yes, 2 is the solution of the given equation.

Answer 1 b)

$\sf \: 7y + 3 = 17$

When y = -3

$\sf \: 7( - 3)+ 3 = 17$

$\sf \: - 21+ 3 = 17$

$\sf \: - 18 \neq \: 17$

$\therefore$ No, -3 isn't the solution of the given equation.

Question 2)

$\sf \: a) \: y - 3 = 7$

$\sf \: b) \: n \div 5 = 9$

$\sf \: c) \: 3x + 5 = 17$

$\sf \: d) \: \dfrac{2}{3} n - 3 = 5$

Question 3)

a) Three times a number n equals 15

b) 3 subtracted from y is 14

c) One third of a number x plus 2 gives 5

Question 4)

a) 2x + 5 = 89

b) x + x + 7 = 39