Answer:
14. x = 6, y = 8
15. x = 5, y = 7
16. x = 7, y = 10
Explanation:
For a parallelogram, the length across the point of intersection of its diagonals are equal.
So that;
14. PT = TR
QT = TS
So that,
2x = y + 4
2x - y = 4 ...........1
x + 2 = y
x - y = -2 ............. 2
subtract equation 2 from 1,
x = 6
substitute the value of x in equation 1,
2 x 6 - y = 4
y = 12 - 4
= 8
x = 6, y = 8
15. PT = TR
QT = TS
x + 2 = y
x - y = -2 .......... 1
2x = y + 3
2x - y = 3 ......... 2
Subtract equation 1 from 2
x = 5
substitute the value of x in equation 1
5 - y = -2
5 + 2 = y
y = 7
x = 5, y = 7
16. PT = TR
QT = TS
y = x + 3
x - y = -3 ......... 1
2y = 3x -1
3x - 2y = 1 ......... 2
Multiply equation 1 by 2 to have;
2x - 2y = -6 ....... 3
subtract equation 3 from 2
x = 7
substitute the value of x in equation 1
7 - y = -3
-y = -7 -3
-y = -10
multiply through by minus
y = 10
x = 7, y = 10