Answer:
the answer is 12 inches
Step-by-step explanation:
there is 1 foot per 12 inches
or
12 inches make a foot
T us assume the two numbers to be "x" and "y".
Then
2x + y = 310
And
x - y = 55
Let us take the second equation and find the value of x in relation to y.
x - y = 55
x = y + 55
Now let us put the value of x in the first equation, we get
2x + y = 310
2(y + 55) + y = 310
2y + 110 + y = 310
3y = 310 - 110
3y = 200
y = 200/3
= 66 2/3
Now putting the value of y in the second equation, we get
x - y = 55
x - (200/3) = 55
3x - 200 = 55 * 3
3x = 165 + 200
x = 365/3
= 121 2/3
So the value of x is 121 2/3 and the value of y is 66 2/3
Answer: 15/7 2 1/7
Step-by-step explanation: First divide 8x-3=x+12 Then add 3 to both sides.
8x=x+15 Subtract x from both sides. 7x=15 Then divide again so 7/7 and 15/7. If you simplify it become 2 1/7
Answer:
Step-by-step explanation:
Let the side of the square base be x
h be the height of the box
Volume V = x²h
13500 = x²h
h = 13500/x² ..... 1
Surface area = x² + 2xh + 2xh
Surface area S = x² + 4xh ...... 2
Substitute 1 into 2;
From 2; S = x² + 4xh
S = x² + 4x(13500/x²)
S = x² + 54000/x
To minimize the amount of material used; dS/dx = 0
dS/dx = 2x - 54000/x²
0 = 2x - 54000/x²
0 = 2x³ - 54000
2x³ = 54000
x³ = 27000
x = ∛27000
x = 30cm
Since V = x²h
13500 = 30²h
h = 13500/900
h = 15cm
Hence the dimensions of the box that minimize the amount of material used is 30cm by 30cm by 15cm
