Solve: -5 + 2
One way to solve this problem is to look at a number line. We start at -5. We are adding a positive number, so we know our answer will be larger than -5. Numbers get larger as you move to the right on the number line. Adding positive 2 means you move 2 spots to the right, putting you at -3.
Erin has 4 apples. She decides to go apple picking, and she picks 13 apples. She then makes a pie and uses 8 apples. How many apples does she have left?
We want to find the number of apples Erin has. She has 4 apples at first. When she goes apple picking, she gets 13 more. 4 + 13 = 17 She then takes away 8 of those apples to make a pie. 17 - 8 = 9 Erin has 9 apples left!
Robbie is 9 years older than Connor. Jacob is 5 years younger than 4 times the age of Connor. The combined age of the 3 boys is 58. How old is Jacob?
Let R represent Robbie's age, J represent Jacob's age, and C represent Connor's age. We can put these variables in equations to represent the parts of the question. Robbie is 9 years older than Connor: R = C + 9 Jacob is 5 years younger than 4 times the age of Connor: J = 4C - 5 We know that the combined age of the boys is 58: R + J + C = 58 Because we know that R is equal to C + 9 and that J is equal to 4C - 5, we can replace R and J in the equation R + J + C = 58. So we now have: C + 9 + 4C - 5 + C = 58 We can combine like terms to get: 6C + 4 = 58 And now we can solve for Connor's age: 6C + 4 = 58 Subtract 4 from both sides 6C = 54 Divide both sides by 6 C = 9 Connor is 9 years old.... but we aren't done yet! The question asks for Jacob's age, not Connor's. We know J = 4C - 5, and we know C = 9, so we can plug 9 in and solve for Jacob's age. J = 4C - 5 J = 4 * 9 - 5 J = 36 - 5 J = 31 Jacob is 31 years old!