Respuesta :

r + t = 42
r = 25

Plug in 25 for r

(25) + t = 42

Isolate the t by subtracting 25 from both sides

t + 25 (-25) = 42 (-25)
t = 42 -25
t = 17

Hope this helps
Since r = 25, t must equal a number that, when added to 25, equals 42.

42 - 25 = 17. t must equal 17.

17 + 25 = 42.