<span>The answer to this question is the attached image below: It is the given dominoes in each number that matches to the same number of dominoes that former options has to the latter choices. As shows the solution is given below as to clearly show the equation which is designated to the desired domino.</span>
add the two equations together
5a+5b=25
-5a+5b=35
------------------
0 + 10b =60
divide by 10
b=6
5a + 5b = 25
5a +5(6) = 25
5a +30 =25
subtract 30 from each side
5a =-5
divide by 5
a = -1
Answer (-1,6)
or a=-1 b=6
He needs 2 cups of sugar if he's tripling the recipe.