Answer:
x = 3.25
y =4.75
Step-by-step explanation:
In order to Solve the following system of equations below algebraically using substitution method we say that;
let;
8x - 4y = 7
..................... equation 1
x + y = 8.......................... equation 2
from equation2
x + y = 8.......................... equation 2
x = 8 - y.............................. equation 3
substitute for x in equation 1
8x - 4y = 7
..................... equation 1
8(8-y) - 4y = 7
64-8y-4y=7
64-12y=7
collect the like terms
64-7 = 12y
57= 12y
divide both sides by the coefficient of y which is 12
57/12 = 12y/12
4.75 = y
y =4.75
put y = 4.75 in equation 3
x = 8 - y.............................. equation 3
x = 8 -4.75
x = 3.25
to check if your answer is correct, put the value of x and y in either equation 1 or 2
from equation 2
x + y = 8.......................... equation 2
3.25 + 4.75 =8
8=8.................... proved
Let the number x.
Then the number divided by 2 gives

Subtract 3.8 from the quotient gives

Hence,


x = 21.6
A. The angles at the intersection of the two lines can be proven to be congruent and complementary . so they meet at a right angle and the lines are perpendicular.
<u>Step-by-step explanation:</u>
In above question, In order to find whether AB ⊥ CD, Using compass construction & rounder , keep the tip at A and cut arcs at line CD . Follow the same process again with tip at B and cut arcs at line CD . Do this both sides of Line CD i.e. on left side of AB & on right side of AB. Now, join the intersection points of both side arcs which are intersecting each other. Now, to prove both are right angle to each other i.e. AB ⊥ CD , can be done by proving congruent and complementary , so they meet at a right angle and Hence , the lines are perpendicular i.e. AB is inclined to CD at angle of 90°.