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:
80 ft²
Step-by-step explanation:
The carpet area will be the area of the pentagon less the 25 square feet taken up by the tree. The area of the pentagon is found by putting the given numbers into the given formula.
pentagon area = 5((7 ft)(6 ft))/2 = 105 ft²
carpet area = 105 ft² -25 ft² = 80 ft²
Peter will need 80 square feet of carpet.
What data is the table referring to?
X + 19 + 7x + 9 = 180
8x + 28 = 180
8x = 180 - 28
8x = 152
X = 152 : 8
X = 19
