Answer:
180 coins
Explanation:
N = number of nickels (no nickels spent)
D = number of dimes initially saved
D' = number of dimes left after spending
1) N = D + 43
2) D' = D - 17
3) N = 2*D' = 2*(D - 17)
Set equations 1) and 3) equal to each other and solve for D:
D + 43 = 2*(D - 17)
D + 43 = 2*D - 34
D = 43 + 34 = 77
N = D + 43 = 77 + 43 = 120 nickels left
D' = D - 17 = 77 - 17 = 60 dimes left
Total coins left = 120 + 60 = 180 coins (I hope this is not too confusing for you)
[ 2x + y = -9 ] x -3
[- 3x +11= y ] x 2
-6x -3y = 27
-6x + 22 = 2y
-6x +27 = 3y
-6x +22 = 2y
5 = y
-6x -3x5 = 27
-6x -15 = 27
-6x = 42
-x = 42/6
-x = 7
x = -7
answer
x = -7
y = 5
78 is the significant figure because in maths 0's are not considered significant. Read more into significant figures to help you out.
Start at 14 on the number line. Since 25 is negative you’re going to be moving to the left. After 14 hops you’ll reach zero, you’re adding -25 so you’ll have to reach a total of 25 hops to the left. You have moved so far 14 hops so you still have 11 to go. Moving 11 more hops to the left results in -11. Now you have reached the total number of hops 25, the negative sign indicated you were moving towards the left. So 14+(-25)=-11
False. A negative number is real, and doesn't have to be a whole. A fraction is real
