This problem is substitution. x^-2-9x^-1+18=0

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

Acoin bank containing only dimes and quarters has 12 more dimes than quarters. the total value of the coins is $11. how many quarters and dimes are in the coin bank?

Stacey filled her 1/2 cup of measuring cup seven times to have enough flour for a cake recipe how much flour does the cake recipe calls for