Question

How do you solve this linear equation using substitution? The decimals keep messing me up. [0.5x+3.2y=9.0]
[0.2x-1.6y=3.6]

Answer 1

Start with .5x + 3.2y = 9, and solve for x.
.5x = 9 - 3.2y
x = (9 - 3.2y)/2 = 4.5 - 1.6y

Then substitute this value in for x in your second equation.
.2 ( 4.5 - 1.6y) = 3.6
.9 - .32y = 3.6
Solve for y.

Then put whatever number you get for y into your x = 4.5 - 1.6y, to find your x value.

Answer 2

if you are not comfortable with decimals, you can always multiply both sides of the equation by a power of ten to get rid of them. e.g.
3.2 * 10 = 32
3.23 * 100 = 323
so in your equation you have:\[0.5x+3.2y=9.0\]\[0.2x-1.6y=3.6\]if you multiply each of these equations by 10 they become:\[5x+32y=90\]\[2x-16y=36\]no more decimals!

I hope this helps you...