How do you use cross products to solve 2/t=5/(t-6)?

2 Answers
May 14, 2018

t=-4

Explanation:

Cross multiply the denominator with numerator like:

2/t=5/(t-6)

2xx(t-6) = 5 xx t

2t-12 = 5t

Add 12 both sides:
2t-12+12 = 5t+12#

2t cancel(-12+12) = 5t+12#

2t = 5t+12
2t-5t = 12 -----> making t the subject by subtracting -5t both sides:

-3t=12

t=-12/3

t=-4

May 14, 2018

t=-4

Explanation:

"using the method of "color(blue)"cross-products"

•color(white)(x)a/b=c/drArrbc=ad

rArr5t=2(t-6)

rArr5t=2t-12

"subtract "2t" from both sides"

5t-2t=cancel(2t)cancel(-2t)-12

rArr3t=-12

"divide both sides by 3"

(cancel(3) t)/cancel(3)=(-12)/3

rArrt=-4

color(blue)"As a check"

Substitute this value into the equation and if both sides are equal then it is the solution.

"left "=2/(-4)=-1/2

"right "=5/(-4-6)=5/(-10)=-1/2

rArrt=-4" is the solution"