Question

If 2a+4b=5 and a is equal to three times b, what is 3a?

Answer 1

To find the value of 3a given that 2a + 4b = 5 and a = 3b, we first solve for b, which is 0.5. Subsequently, we find a to be 1.5. Multiplying a by 3 gives us 3a equal to 4.5.

Step-by-step explanation:

The question requires us to find the value of 3a given the system of equations where 2a + 4b = 5 and a is equal to three times b (a = 3b). We can solve this by substituting the second equation into the first to find the values of a and b.

Using a = 3b, we substitute into the first equation to get 2(3b) + 4b = 5. Simplifying this we get 6b + 4b = 5, which further simplifies to 10b = 5. Solving for b, we find b = 0.5. Now that we have the value of b, we can find a by substituting b back into the equation a = 3b, which gives us a = 3(0.5) = 1.5. Finally, to find 3a, we simply multiply the value of a by 3, which results in 3(1.5) = 4.5.

Answer 2

3A = 3(1 1/2) = 4 1/2

Step-by-step explanation:

2A + 4B = 5

A = 3B

2(3B) + 4B = 5 [substitute the A for the 3B]

10B = 5 so B = 1/2 [now plug the info in]

2A + 4(1/2) = 5

2A + 2 = 5 [subtract 2 from both sides of the equation]

2A = 3 [divide by 2 to isolate A]

A = 3/2 [now plug in the answers to check your work]

2(3/2) + 4(1/2) = 5

6/2 + 4/2 = 3 + 2 = 5