How do you evaluate #3s t ^ { 2} - s ^ { 2}# when #s=4# and #t=7#?

1 Answer
Aug 5, 2017

#572#

Explanation:

'Evaluate' means to find a value or number for.

You have to replace a variable by a number.

Substitute #color(red)(4)" for " color(red)(s) and color(blue)(7)" for "color(blue)(t)#

#3color(red)(s)color(blue)(t)^2 - color(red)(s)^2#

#=3color(red)((4))color(blue)((7))^2 - color(red)((4))^2#

#=3xx4xx49-16#

#=572#