The interest on an investment varies directly as the rate of interest. If the interest is $41 when the interest rate is 4%, find the interest when the rate is
7.2%

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota

Write an inequality for this sentence the quotient of a number and -5 increased by 4 is at most 8