In what step is there first an error. Please explain the error, what misunderstandings the student has and how to correctly work the problem.
Given: 2(10 −13) +9 = −34 + 60
Step 1: 20 − 26 + 9 = −34 +60
Step 2: 17 = −34 +40
Step 3: 51x = 40
Step 4: =
40
51

Tim open up a new saving account with a $50 deposit and plant to deposit $20 per week into the same account. write an expression to represent the total amount in his savings account.

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?

7+(3n++8) what is the answer to this?