Let x be the unknown number
2x +7 = 39
2x+7-7 = 39-7
2x = 32
2x/2 = 32/2
x=16
You use the balance method to solve. First, you cancel the +7 by subtracting the 7 ON BOTH SIDES to balance the equation.. After that, you are left with 2x, where you will need to isolate the x by dividing by 2 ON BOTH SIDES to balance it.
Hope this helps
330100 is to the nearest ten
If each of the 36 cans of vegetables were corn the cost would be 0.40*36 or $14.40. This is obviously not enough. For every tomato can you buy instead of corn the price goes $0.80 -$0.40 or $0.40 up. Knowing this all you need is to find how many corns to replace. To do this find the difference between the real cost and the all corn cost. This is $20.8-$14.4 or $6.40. Now to find the number of corns to be replaced just divide this by 0.40 to get 16. That means 16 corns need to be replaced by tomatoes. So there is 20 cans of corn and 16 cans of tomatoes. The answer is 20 cans of corn.
1054 (9-8x)=78
(9-8x)= (78÷1054)
9-8x = 0.074
-8x=0.074-9
-8x=-8.926
x= (-8.926÷-8)
x= 1.1157