The answer would be D and E
Answer:
36 years
Step-by-step explanation:
Let
x = Elga's age
Alvin's age = x + 7
Sum of their ages = 79
Sum of their ages = Alvin's age + Elga's age
79 = (x + 7) + x
79 = x + 7 + x
79 = 2x + 7
79 - 7 = 2x
72 = 2x
x = 72/2
x = 36
Elga's age = x = 36 years
Alvin's age = x + 7
= 36 + 7
= 43 years
Answer: =80/11
Step-by-step explanation:x=80-10x
We move all terms to the left:
x-(80-10x)=0
We add all the numbers together, and all the variables
x-(-10x+80)=0
We get rid of parentheses
x+10x-80=0
We add all the numbers together, and all the variables
11x-80=0
We move all terms containing x to the left, all other terms to the right
11x=80
x=80/11
x=7+3/11
Let
x---------> the length of the rectangle
y--------> the width of the rectangle
we know that
A=84 ft²
[area of rectangle]=x*y-----> 84=x*y-----> equation 1
x=y-5------> equation 2
substitute 2 in 1
84=[y-5]*y-----> 84=y²-5y---------> y²-5y-84=0
using a graph tool-----> to resolve the second order equation
see the attached figure
the solution is
y=12
x=y-5-----> x=12-5-----> x=7
the answer isthe length of the rectangle is 7 ftthe width of the rectangle is 12 ft
Both of these problems will be solved in a similar way, but with different numbers. First, we set up an equation with the values given. Then, we solve. Lastly, we plug into the original expressions to solve for the angles.
[23] ABD = 42°, DBC = 35°
(4x - 2) + (3x + 2) = 77°
4x+ 3x + 2 - 2 = 77°
4x+ 3x= 77°
7x= 77°
x= 11°
-
ABD = (4x - 2) = (4(11°) - 2) = 44° - 2 = 42°
DBC = (3x + 2) = (3(11°) + 2) = 33° + 2 = 35°
[24] ABD = 62°, DBC = 78°
(4x - 8) + (4x + 8) = 140°
4x + 4x + 8 - 8 = 140°
4x + 4x = 140°
8x = 140°
8x = 140°
x = 17.5°
-
ABD = (4x - 8) = (4(17.5°) - 8) = 70° - 8° = 62°
DBC =(4x + 8) = (4(17.5°) + 8) = 70° + 8° = 78°