Take the 89 times 5 tests. You get 445 total score you need for an average of 89. Add 82, 89, 92, 87=350 445-350=95 They must get a 95 on next test to get the average of 89
Let's call the three numbers x, y, and z.
The numbers are 3, 12, and 5.
x + y + z = 20
y = 4x
x + z = 8
We can rewrite the first equation because y is 4x, so
x + 4x + z = 20
5x + z = 20
And now we can use simultaneous equation rules to solve
5x + z = 20
x + z = 8
5x + z = 20
5x + 5z = 40
(subtract)
-4z + -20
÷ -4
z = 5
x + z = 8
x + 5 = 8
x = 3
y = 4x
y = 4 × 3
y = 12
I hope this helps!
Answer:
a.
Step-by-step explanation:
To find the surface area of a cylinder, use the formula SA = 2(pi)(radius^2) + 2(pi)(radius)(height).
So now, plug in what you know.
SA = 2(3.14)(5^2) + 2(3.14)(5)(9)
SA = (6.28)(25) + (6.28)(45)
SA = 157 + 282.6
SA = 439.6 square cm
439.6 square cm is your surface area
Answer:
l = 32.5 units, w= 27.5 units, A = 893.75 units²
Step-by-step explanation:
width is w
length is l = 5+w
P = 2( l+w) , substitute l for 5+w
P = 2(5+w+w)
P = 2(5+2w)
P = 10 +4w
P = 120
10 +4w = 120
4w = 120-10
4w = 110
w= 110/4
w= 27.5 units
l = 5+w = 5+ 27.5 = 32.5 units
A = l*w = 27.5 * 32.5 = 893.75 units ²
