He grates 6/8 pounds of cheese in all.
For this problem, you just have to add the numerators and keep the denominators.
4/8 + 2/8 = 6/8.
Remember, if the denominator is the same, just add the numerator.
very simple, we use the formula sin(a+b)=sinacosb +
sinbcosa and sin(20)=2sinacosa
5pi = 2pi/3+3pi/3,
First, we use sin(a+b)=sinacosb + sinbcosa
sin(5pi/3)=sin(2pi/3+3pi/3)=
sin(2pi/3+pi)=
sin(2pi/3)cos(pi) +sin(pi)cos(2pi/3)
but we know that sin(pi)=
0, and cos (pi) = -1, so sin(5pi/3)=
- sin(2pi/3)
now, use sin(2a)=2sinacosa,
sin(5pi/3)= - sin(2pi/3)= -2sin(pi/3)cos(pi/3)
sin<span>(5pi/3)=
-2sin(pi/3)cos(pi/3)</span>
<span>sin(pi/3)= 0.86,
cos(pi/3)=0.5, finally we have </span>sin<span>(5pi/3)= -0.86 x 0.5= -0.43</span>
89+93+98 = 280
360 - 280 = 80 marks is needed for the last test