# Equation - 7th grade (12y) - examples - page 23

1. Negative in equation 2x + 3 + 7x = – 24, what is the value of x?
2. Sum of four numbers The sum of four consecutive natural numbers is 114. Find them.
3. Solve 2 Solve integer equation: a +b+c =30 a, b, c = can be odd natural number from this set (1,3,5,7,9,11,13,15)
4. Bed time Tiffany was 5 years old; her week night bedtime grew by ¼ hour each year. If, at age 18, her curfew time is 11pm, what was her bed time when she was 5 years old?
5. Supplementary angles One of the supplementary angles is larger by 33° than the second one. Calculate the angles size.
6. Poplar How tall is a poplar by the river, if we know that 1/5 of its total height is a trunk, 1/10th of the height is the root and 35m from the trunk to the top of the poplar?
7. Mysterious number The magician thinks the number: "The mysterious number is first divided by minus five, dividing the result by three, multiplying the number by ten, and dividing the resulting number by minus four. This gives result 5. Can you reveal the mysterious number?
8. Unknown number I think the number. I'll reduce it to its one-third. The result is then increased by one-third, and I get the number 12.
9. A man A man spends 5/9 of his money on rent, and 5/16 of the remainder on electricity. If the final balance remaining is 550 find how much was spent on rent
10. Last page Two consecutive sheets dropped out of the book. The sum of the numbers on the sides of the dropped sheets is 154. What is the number of the last page of the dropped sheets?
11. Twenty Twenty rabbits are put in 4 cells so that there are different number of rabbits in each cell contains at least 3 rabbits. What is the largest possible number of rabbits in one cell
12. Taxi A taxi ride costs \$3 plus \$2.50 per mile. Write and Graph an equation in two variables that represents the total cost of a taxi ride.
13. Find x Solve: if 2(x-1)=14, then x= (solve an equation with one unknown)
14. Flour Kim needs 3/4 cup of flour to make 12 cookies. How much flour would she need to make 60 cookies?
15. The average The average of one set of 4 numbers is 35. The average of another set of number is 20. The average of the numbers in the two sets is 30. How many numbers are there in the other set?
16. Boats Three-quarters of boats are white, 1/7 are blue and 9 are red. How many boats do we have?
17. A number A number increased by 7.9 is 8.3
18. MG=7x-15, MG=7x-15, FG=33, x=? Point M is the midpoint of FG. Find unknown x.
19. Which Which decimals when subtracted equal 3.89: a - b = 3.89
20. The quotient The quotient of g and 55 is the same as 279. What is g?

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