Question

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30 ?

Answer 1

Answer:

a= 60

Step-by-step explanation:

1/2a+2/3b=50, when b=30

Let's first subsitute 30 into b:

1/2a+2/3(30)=50

According to the order of operations, we must multiply 2/3 and 30 first.  So:

2/3 times 30 equals 20.

2/3 times 30/1.  3 goes into 30 ten times, so 2 times 10= 20.

Now we got:

1/2a+20=50

Since 20 and 50 are like terms, you want to geth those two together.  So, move the positive 20 to the other side where 50 is.  Since 20 got moved to the opposite side, it changes signs and becomes negative.

So:

1/2a=50-20        

50-20= 30

1/2a=30

Multiply each side by 2 because 2 is the only number that'll make the variable a just 1a.

1/2a times 2= 1a

30 times 2= 60, so:

1a= 60, which is also a= 60.

So a= 60.

Answer 2

Answer:

Step-by-step explanation:

1/2a+20=50

1/2a=30

a=10