Joanna bought 7 notebooks and 14 pencils
Step-by-step explanation:
Step 1 :
Let x denote the number of notebooks and y denote the number of pencils Joanna bought.
Cost of one notebook = $ 2.30
Cost of one pencil = $1.42
Step 2 :
Total of notebooks and pencils bought = 21
=> x + y = 21 => y = 21-x
Total cost of notebooks and pencils = $35.98
=> 2.3x + 1.42y = 35.98
Substituting y = 21- x here , we have,
2.3x + 1.42 ( 21-x) = 35.98
2.3x + 29.82 - 1.42x = 35.98
0.88 x = 6.16
=> x = 7
y = 21-x = 21-7 = 14
Step 3 :
Answer :
Joanna bought 7 notebooks and 14 pencils
Answer:
20
Step-by-step explanation:
80% of 25 is 20, even if you put it into a calculator
Answer:
The area of the rectangle is 1222 units²
Step-by-step explanation:
The formula of the perimeter of a rectangle is P = 2(L + W), where L is its length and W is its width
The formula of the area of a rectangle is A = L × W
∵ The length of a rectangle is 5 less than twice the width
- Assume that the width of the rectangle is x units and multiply
x by 2 and subtract 5 from the product to find its length
∴ W = x
∴ L = 2x - 5
- Use the formula of the perimeter above to find its perimeter
∵ P = 2(2x - 5 + x)
∴ P = 2(3x - 5)
- Multiply the bracket by 2
∴ P = 6x - 10
∵ The perimeter of the rectangle is 146 units
∴ P = 146
- Equate the two expression of P
∴ 6x - 10 = 146
- Add 10 to both sides
∴ 6x = 156
- Divide both sides by 6
∴ x = 26
Substitute the value of x in W and L expressions
∴ W = 26 units
∴ L = 2(26) - 5 = 52 - 5
∴ L = 47 units
Now use the formula of the area to find the area of the rectangle
∵ A = 47 × 26
∴ A = 1222 units²
∴ The area of the rectangle is 1222 units²
Answer:
Um sorry if its wrong but I think its that it gets bigger as you go on.
Step-by-step explanation:
If I'm not mistaken, x=1 2/3 or 1.66
