#4 have no answer, there are 2 variables but only 1 representation.
#6.
\(x\times x + 2x - 35 = 0\\ x^2 + 2x - 35 = 0\\ (x+7)(x-5)=0\\ x=-7\\ \text{OR}\\ x=5\)
None is the answer for #6.
#7.
\(\sqrt3^{\sqrt2}\times \sqrt3^{(-\sqrt2)}\\ =\sqrt3^{\sqrt2} \times \dfrac{1}{\sqrt3^{\sqrt2}}\\ = 1\)
#7 answer = C
#8.
\(\sqrt2^{\sqrt2^{\sqrt2}}\\ \text{First we need to find what's }\sqrt2^{\sqrt2}\\ \sqrt{2}^{\sqrt{2}}\\ = 2^{\frac{1}{2}^\sqrt{2}}\\ = 2^{\frac{\sqrt2}{2}}\\ \mbox{We will do the same thing to }\sqrt2^{\sqrt2^{\sqrt2}}\\ \sqrt2^{\sqrt2^{\sqrt2}}\\ ={2^{\frac{\sqrt2}{2}}}^{\sqrt2}\\ =2^{\frac{\sqrt2^2}{2}}\\ = 2^1\\=2\)
#8 answer = A
#9.
\(\sqrt2^{-9+3}\\ =2^{\frac{-6}{2}}\\ =2^{-3}\\ =\frac{1}{8}\)
#9 answer = B
#10. Given the 2 angles are supp. Therefore the sum of 2 angles is 180 degrees.
\((x-15)^{\circ}+2x^{\circ}=180^{\circ}\\ (3x-15)^{\circ}=180^{\circ}\\ 3x^{\circ}=195^{\circ}\\ x^{\circ}=65^{\circ}\)
Therefore #10 answer = A
