We have 75 mL of 4% sugar solution.
We have to add a 30% sugar solution to make a 50% 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%.
