3⁴-21÷7
According to PEMDAS ( order of operations):
First, Do exponents before multiplying or dividing: 3^4
81-21÷7
Then, divide before subtracting (27÷7 )
81- 3
Finally, subtract
78
- 2 because we obtain : - 2x - 2y = - 16 ;
We solve the system:
5x + 2y = 30
-2x - 2y = -16
_____________(+)
3x / = 14;
x = 14/3;
y = 8 - 14/3;
y = 24/3 -14/3;
y = 10/3;
The solution of the system is ( 14/3 ; 10/3 )
Angle 2 and 4 are vertical angles(opposite) thus they are congruent... set
9x+4=14+8x
9x-8x=14-4
X=10
Now substitute x back into angle 4 and solve
