Answer:
There were 61 bagels and 23 coffee sold
Step-by-step explanation:
Let us solve the question
∵ The number of bagels and coffee sold by a bagel shop yesterday
can be modeled using the equation b + c = 84
∴ b + c = 84 ⇒ (1)
∵ Their sales for the same day can be modeled using the equation
2b + c = 145
∴ 2b + c = 145 ⇒ (2)
Let us solve the system of equations using substitution
→ Subtract the two sides of equation (1) by b to find c in terms of b
∵ b - b + c = 84 - b
∴ c = 84 - b ⇒ (3)
→ Substitute c in equation (2) by equation (3)
∵ 2b + 84 - b = 145
→ Add the like terms on the left side
∴ (2b - b) + 84 = 145
∴ b + 84 = 145
→ Subtract 84 from both sides
∵ b + 84 - 84 = 145 - 84
∴ b = 61
→ Substitute the value of b in equation (3) to find c
∵ c = 84 - 61
∴ c = 23
∴ There were 61 bagels and 23 coffee sold.