can't type thta trignale thingie so subsitute with x
79=(710)-(7x)
we can multipily what we know
79=7 times 9=63
710=7 times 10=70
now we have
63=70-(7x)
add (7x) to both sides
(7x)+63=70
subtract 63 from boths ides
(7*x)=7
divide both sides by 7
x=1
the answe ris traignle is equal to 1
