Answer:
B
Step-by-step explanation:
Answer:
use -9 to multiply the first equation
use -4 to multiply the second equation.
Step-by-step explanation:
5x-4y=28.....eqn (1)×-9
3x-9y=30....eqn(2)×-4
-45x+36y=-252
-(-12x+36y=-120)
therefore, -33x÷33 =-132÷-33
x=4.
substitute (x=4) in any of the equation. I'm just going to use eqn 1.
5x-4y=28
5(4)-4y=28
20-4y=28
-4y =28-20
-4y÷-4 = 8÷-4
y=-2
so, x=4, y=-2
Note: for proof of answers substitute the answers for x and y and see if you have the same result...e.g
5(4)-4(-2)=28.
We are given
△ABC, m∠A=60° m∠C=45°, AB=8
Firstly, we will find all angles and sides
Calculation of angle B:
we know that sum of all angles is 180
m∠A+ m∠B+m∠C=180
we can plug values
60°+ m∠B+45°=180
m∠B=75°
Calculation of BC:
we can use law of sines

now, we can plug values



Calculation of AC:

now, we can plug values



Perimeter:

we can plug values


Area:
we can use formula

now, we can plug values

...............Answer
The answer is C 9/2 x 1/3