twice as many cats (as) dogs.
c = 2d [not true]
Three less than twice as many cats (as) dogs.
c = 2d - 3
210 combined,
c + d = 210
Subtracting,
-d = 2d - 3 - 210
-3d = -213
d = 71
Answer: 71
Answer:
The length of the unknown side x is 4 cm
Step-by-step explanation:
we know that
The perimeter of a polygon is equal to the sum of its length sides
Remember that
1 cm=10 mm
In this problem we have
AB=45 mm ------> convert to cm -----> AB=45/10=4.5 cm
BC=10 cm 4 mm -----> convert to cm -----> BC=10+4/10=10.4 cm
CD=5 cm 6 mm -----> convert to cm -----> CD=5+6/10=5.6 cm
DE=35 mm ------> convert to cm -----> DE=35/10=3.5 cm
EA=x cm
P=280 mm ------> convert to cm -----> P=280/10=28 cm
The perimeter of the irregular polygon is equal to
P=AB+BC+CD+DE+EA
substitute the values
28=4.5+10.4+5.6+3.5+x
28=24+x
x=28-24
x=4 cm
"31-inch piece of steel is cut into three pieces"
Call the pieces a,b,c
a + b + c = 31
"second piece is twice as long as the first piece"
b = 2a
"third piece is one inch more than seven times the length of the first piece"
c = 1 + 7a
Ok, we have our equations, let's substitute the second and third into the first.
a + 2a + 1 + 7a = 31
10a + 1 = 31
10a = 30
a = 30/10 = 3
b = 2a = 6
c = 1 + 7a = 22
Check: 3 + 6 + 22 = 31, good
Answer: 3 inches, 6 inches, 22 inches
