The answer would be d , because you have to add how many of each fish to equal up to the sum of 420 . which is x y . so the first equation is x + y = 420 . then it says he bought 6 times as many parrotfish as he did angelfish so you would have to multiply x which represents angelfish by 6 . to get the second equation of y = 6x .
Corresponding angles are angles that are equal in degrees and in this case it is <8 and <4 but there is also <5 and<7.
Just guess and check. For example, for the first on the left, I guessed 3 to begin with. 3 + 3 + 3 = 9, but 10 + 3 = 13, so 3 is not the answer. I then guessed 5. 5 + 5 + 5= 15, and 10 + 5= 15, so star = 5.
How you find the area of a triangle is base × height ÷ 2. So the equation would be 6×3=18 18÷2=9, so the answer is 9. Hope this helped!
