Using y2-y1/x2-x1 m=24/6 so the slope is +4
<span>ralph = r
sara = s
ralph is TODAY, 3 times older, so if sara is "s" old, ralph is 3s
r = 3s
in 6 years, ralph will be 2 times as old as sara THEN,
in 6 years ralph will be TODAY's age plus 6, so r + 6
so if sara is "s" old, r+ 6 = 2s
r + 6 = 2s</span>
<span>For a rotation of 90o: (x, y) ⇒ (–y, x)
T(3,4) ⇒⇒⇒ T'(-4,3)
W(-2,-1) ⇒⇒⇒ W'(1,-2)
x(-3,3) ⇒⇒⇒ x'(-3,-3)
see the attached figure
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