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:
42.6cm
Step-by-step explanation:
The sum total of all the sides of the shape is the perimeter of the shape. Hence;
Perimeter = x+3 + 4 + x+9 + 2x+5
Perimeter = 4x + 21
Given
Area of the figure = 75cm^2
Area = (x+3)(2x+5) + (2x+1)(6)
75 = 2x²+5x+6x+15+12x+6
75 = 2x²+23x+21
2x²+23x+21-75 = 0
2x²+23x-54 = 0
x = -23±√23²-4(2)(-75)/4
x = -23±√529+600/4
x = -12±√1129/4
x = -12+33.6/4
x = 21.6/4
x = 5.4
Recall that;
Perimeter = 4x+21
Perimeter = 4(5.4) + 21
Perimeter = 21.6+21
Perimeter = 42.6cm
Hence the perimeter is 42.6cm
Step-by-step explanation:
1. yes 4+16 = 20
2. yes 32 - 4 = 28
3. yes 4(10) = 40
4. no 24/6 = 4
Answer:
x = - 3 ±
Step-by-step explanation:
Given
4x² + 24x = 4 ( divide through by 4 )
x² + 6x = 1
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(3)x + 9 = 1 + 9
(x + 3)² = 10 ( take the square root of both sides )
x + 3 = ± ( subtract 3 from both sides )
x = - 3 ±
Answer:
<u>96 ft</u> is the perimeter of the figure.
Step-by-step explanation:
9 + 9 + 9 + 9 + 9 + 9 + 12 + 30 = 96
Have a nice day!