Answer:
Step-by-step explanation:
The first four
ok first you do the small one. 13 * 5 * 1/2 = 32.5 then you do 35 *1/2=17.5. you then divide 32.5/17.5=1.86
9x^2+kx+1=0
k= -9x-1/x
that's my answer
I think I help you
hope it's help