10b - 60
explanation: distribute
13=1/6y+2x
-1/6y -1/6y
-1/6y+13=2x
-13 -13
-1/6y=2x-13
*-6 *-6
y=-12x-13
*I multiply it by -6 because -6 is the reciprocal of -1/6, and I can't divide -1/6, actually I can, but it just going to be more confusing that way, and the fastest way to get rid of the -1/6 when you solving this type of equation is multiply it by its reciprocal.
<span>We have 75 mL of 4% sugar solution.
We have to add a 30% sugar </span><span>solution to make a 50% </span><span>sugar solution.
75 * .04 + .30x = .50 * (75 +x)
3 + .30x = 37.5 +.50x
I can't get the equation to solve.
Did you type it correctly? For one thing, you have the percentages typed as .30 % and 4%. Are the decimal places in the correct positions?
Also, no matter how much 30% sugar solution you add, it will NEVER increase to 50%.
</span>
Let's solve for y.
4x+7y=28
Add -4x to both sides.
4x+7y+−4x=28+−4x
7y=−4x+28
Divide both sides by 7.
7y/7=−4x+28/7
y=−4/7x+4