Answer:
Step-by-step explanation:
<u>Janet ⇒ 3 postcards ⇒ $1.05 </u>
- Cost of postcard: 1.05/3 = $0.35
<u>Rosi ⇒ 5 postcards ⇒ $1.75 </u>
- Cost of postcard: 1.75/5 = $0.35
<u>Tanya ⇒ 8 postcards ⇒ $2.80</u>
- Cost of postcard: $2.80/8 = $0.35
<u>We see in all 3 cases cost of postcard is same, the cost and numbers are proportional and the relationship is:</u>
We are asked to express r in terms of A, P, and t.
We first divide both sides of the equation by t, which gives us

,
then, dividing both sides by P, we have

.
Swap the sides:
Finally subtracting 1 from both sides gives us

.
Answer:
40/8
Step-by-step explanation:
40 divided by 8 is 5.
The way you can check this is by multiplying 8*5
Basically what number times 8 will equal 40
Length = x + 2 (because it is 2 cm more than x)
Width = 2x - 5 (5 cm lest than 2x)Area = 54 cm2 this is the formula to find the area Length × Width = Area (x + 2)(2x - 5) = 542x2 - x - 10 = 54 (this is you area)
Subtract 54 on both sides of equation to make the right side zero. 2x2 - x - 64 = 0 then use the quadratic formula x = (-b ± √(b2 - 4ac)) / 2a where:a = 2b = -1c = -64 Plug in these values into the formula. x = (1 ± √(1 - 4(-128))) / 4 x = (1 ± √(513)) / 4 x = (1 ± 22.65) / 4 x = (1 + 22.65) / 4 and x = (1 - 22.65) / 4 x = 5.91 and x = -5.41 Check the validity of the x values by adding them to the length and width. If the length or width should be a negative value, then that value of x is not acceptable. Now x = 5.91 Length = 5.91 + 2 (positive value.)Width = 2(5.91) - 5 ( positive value.) x = 5.91 If we look at this -- x = -5.41, Both length and width will be negative values. We reject this value of x. The answer is x = 5.91
Hope I helped and sorry it was really long