You know angles B and C are both 60°, the values of the angles in an equilateral triangle. Since the sum of angles in a quadrilateral is 360°, you have
B + C + x + y = 360°
60° +60° + x + y = 360°
x + y = 240°
1. 3x - 2y = 0 => y = 3/2x
4x + 2y = 14<=> 4x + 2*(3/2x) = 14<=> 7x = 14<=> x = 2 & y = 3
2.3p + q = 7=> q = 7 - 3p
2p - 2q = -6<=> 2p - 2*(7-3p) = -6<=> 2p - 14 + 6p = -6<=> 8p = -6 + 14 = 8<=> p = 1 & q = 4
3.3x - 2y = 1=> x = (1+2y)/3
8x + 3y = 2<=> 8*(1+2y)/3 + 3y = 2<=> 8*(1+2y)/3 - 2 = -3y<=> 3*(8*(1+2y)/3 - 2) = -3*(3y)<=> 8*(1+2y) - 6 = -9y<=> 8 + 16y - 6 = -9y<=> 2 = -25y<=> y = -2/25 & x = 7/25
Https://youtu.be/3y1U0sntOsI
Answer:
Step-by-step explanation:
4x=12
x=12/4
x=3 answer
y=4*3=12 answer.
z=8-3=5 answer.
proof
3+12+5=20
20=20
The sequence is arithmetic since the common difference that is equal
d=11-15=7-11=-4
a(n) = a1 +(n-1)d
a1=15
=
a(n) = 15+(n-1)-4
