What is the value of a in the equation 3a+b=54 , when b=9 ?

Use substitution method

3a+9=54

3a+9-9=54-9

3a= 45

divide by 3

3a/3= 45/3

a= 15

Answer is a= 15

a = 15

Step-by-step explanation:

3a + b = 54

3a + 9 = 54

3a + 9 - 9 = 54 - 9

3a = 45

3a divided by 3 = 45 divided by 3

a = 15

3 x 15 + 9 = 54

45 + 9 = 54

54 = 54

no

step-by-step explanation:

2-7=-5

7-2=5

when you combing like terms for ech expression, 5 and -5. these numbers are not equal to each other.

the final amount you will pay is $68.04.

the tip is determined by the pre-tax amount, so we calculate the tip based on the original bill, not after we've added sales tax.

to find the tip:

we can divide 54.00 by 100 to get 1% of 54. then we multiply that by 18.

54 / 100 = .54

.54 x 18 = 9.72

tip = 9.72$

to find the tax:

we can divide 54.00 by 100 to get 1% of 54. then we can multiply that by 8 to get 8%.

54 / 100 = .54

.54 x 8 = 4.32

tax= 4.32

now we can add the tip and tax to the bill to get our total.

54 + 9.72 + 4.32 = 68.04

total: $68.04

step-by-step explanation: