It’s rational because the square root of 0.49 is 0.7
Answer:
24 oz has the lowest cost per ounce.
Step-by-step explanation:
12 oz ---> $2.49
1 oz --> $2.49/12
1 oz --> $0.2075
14 oz --> $3.15
1 oz --> $3.15/14
1 oz --> $0.225
20 oz --> $5
1 oz --> $5/20
1 oz --> $0.25
24 oz --> $4.56
1 oz --> $4.56/24
1 oz --> $0.19 ..........this is the lowest cost per ounce
36 oz --> $7.2
1 oz --> $7.2/36
1 oz --> $0.2
What must be true is the expression will actually be adding 10 + (+ x), because of the two marks you have to make when subtracting by a negative.
The subtraction sign is also the negative sign. So in this case, the expression is also saying -x, which means there is two negative signs.
A double negative is a positive, so in this case the x will be turned to a positive integer.
If this is still too confusing, she can plug in a number to replace x. Let’s try it with -2:
Ex. 10 - (-2)= 12.
The two negative signs turn into one positive sign, AKA an addition sign. So, the above expression can be simplified as 10 + 2, or 12.