You're using inverse operation to solve this equation. Now you just have to think about it. What number plus 20 would equal the same number squared? The answer would be 5, since 5+20=5^2 25=25 The statement above is true :) Another number that would work for the equation would be x= -4 -4+20=-4^2 16=16 The statement above is also true so your answer would be x=-4 and 5
"I am going to explain this using the substitution method, considering it appears to be the best in this situation.We know (from the bottom equation) that y can equal 3x+20. Using this knowledge, we substitute the y in the top equation for 3x+20. Now, we have an equation that looks like this:3x+20=x^2+2xNow we need to move x to one side and then do some radicals (square roots).Subtract the 2x on the right (since it is smaller, negatives = NONONO), which will give youx+20=x^2Now, we take the square root of both sides to get rad(x+20)=xNow we have to simplify. 20 doesn't have a square root, but 4 goes into 20, and 4 has a square root of 2. This now becomes2rad(x+5)"
