Zach mows lawns. He charges $5 plus $3 per hour. Alex also mows lawns. He charges $2 plus $4 per hour. How many hours do they need to work to make the same amount?

Find the value of the variable and the length of each secant segment.

7x+8y=-18, 4x-9y=-3 solve the system of equations

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is