Question

A and b are positive integers and 7a+ 5b= 49. Find the values of a and b.

3.1 What is a?
2 What is b?

Answer 1

B = 49/5 - 7a/5

A = = -5b/7 + 7

Explanation:

Given that,

7a+ 5b= 49

Solution:

Solving for a:

Add -5b to both sides:

• 
  `7a+5b - 5b=49 - 5b`
• 
  `7a = - 5b + 49`

Divide both sides by 7:

• 
  `\cfrac{7a}{7} = \cfrac{ - 5b + 49}{7}`
• 
  `a = \cfrac{ - 5b}{7} + 7`

Hence,a = -5b/7 + 7.

Solving for b:

Add -7a to both sides:

• 
  `7a+5b+( - 7a)=49+(−7a)`
• 
  `7a + 5b - 7a = 49 - 7a`
• 
  `5b = 49 - 7a`

Divide both sides by 5:

• 
  `\cfrac{5b}{5} = \cfrac{49 - 7a}{5}`
• 
  `b = \cfrac{49}{5} - \cfrac{7a}{5}`

Hence,b = 49/5 - 7a/5.