Solve the following problems using algebra (i.e., with equations). To help you get started, you may wish to employ Pólya’s four problem-solving steps. Also, to figure out which equations to use, you...

Sergio spends38" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">3838of his monthly income on rent. Sergio’s rent is $930. What is Sergio’s monthly income?

Molly made some Saskatoon berry tarts. Molly gave14" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">1414of her tarts to Alanis. Then Molly gave23" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">2323of the remaining tarts to Kateri. At that point, Molly had 3 tarts left. How many Saskatoon berry tarts did make intially?

There are 90 hockey sticks arranged into 4 groups. The second group has 9 more hockey sticks than the first group. The third group has half as many hockey sticks as the second group. The fourth group has 5 fewer hockey sticks than the sum of the hockey sticks in the second and third groups. The number of hockey sticks in the fourth group is also twice as many as the number of hockey sticks in the first group. How many hockey sticks are in each group?