Question

4a-b=10 . 2a + 3b=12​

Answer 1

a = 3

b = 2

Explanation:

Solve 4a - b = 10 for b:

• 
  `4a - b = 10`
• 
  `4a - b - 4a = 10 - 4a` (Subtract 4a from both sides)
• 
  `-b = -4a +10`
• 
  `(-b)/(-1) = (-4a+10)/(-1)` (Divide both sides by -1)
• 
  `b = 4a - 10`

Substitute 4a - 10 for b in 2a + 3b = 12

• 
  `2a + 3b = 12`
• 
  `2a + 3(4a-10)=12`
• 
  `2a + 12a -30 = 12` (Simplifying)
• 
  `14a - 30 = 12` (Simplifying
• 
  `14a - 30 + 30 = 12 + 30` (Add 30 to both sides)
• 
  `14a = 42`
• 
  `(14a)/(14) = (42)/(14)` (Divide both sides by 14)
• 
  `a = 3`

Substitute 3 for a in b = 4a - 10

• 
  `b = 4a - 10`
• 
  `b = 4(3) - 10`
• 
  `b = 12 - 10`
• 
  `b = 2`

Therefore, a = 3 and b = 2.