Answer: #20, x = 3
#21, x = 1/2
Step-by-step explanation:
#20) x + 4 + x + 2+ x + 5 = x + 3 +x+3+x+1+x+1
3x + 11 = 4x + 8
<u>-3x -3x</u>
11= x + 8
<u> - 8 - 8</u>
3 = x
#21) 12x(5) = 6x + 9 + x + 10 + x + 7
60x =8x + 26
<u> -8x -8x</u>
52x = 26
divide both sides by 52
x = 1/2
ANSWER
The correct answer is option B
EXPLANATION
The equations are
and
When we multiply the second equation by 
, we obtain;
When we combine this new equation with equation (1).
We can see that 
has been eliminated from the equation.
We can then, solve for 
and then substitute the result in to any of the equations to find .
Hence the correct answer is option B
The lawn area of uniform width can be written as follows:
A = (40 + 2x) * (35 + 2x) - (40) * (35)
Where,
x: width of the lawn
Substituting the value of the area we have:
316 = (40 + 2x) * (35 + 2x) - (40) * (35)
Rewriting:
316 = 1400 + 80x + 70x + 4x ^ 2 - 1400
Rewriting we have:
4x ^ 2 + 150x - 316 = 0
Solving the polynomial we have:
x1 = - 79/2
x2 = 2
Taking the positive root we have that the grass width des:
x = 2 yards
Answer:
The width of the lawn that surrounds the garden is:
x = 2 yards
Answer:
C=$(4.30xy+5.40(xz+yz))
Step-by-step explanation:
Surface Area of a Cuboid=2(LW+LH+HW)
Since the top is open
Surface Area = LW+2(LH+HW)
If Length = x feet,
Width =y feet
Height = z feet
Surface Area = xy+2(xz+yz)
Area of the base=xy
If it costs $4.30 per square foot to build the base
Cost of the base=Cost Per Square Foot X Area = $4.30xy
Area of the sides =2(xz+yz)
If it costs $2.70 per square foot to build the sides
Cost of the sides=Cost Per Square Foot X Area of the sides
= 2.70 X 2(xz+yz)
=5.40(xz+yz)
Cost of Constructing the Box = Cost of Constructing the Base + Cost of Constructing the Sides.
Therefore,
C=$(4.30xy+5.40(xz+yz))
