Paul has grades 63 and 81 on his first two test. what must he score on his third test in order to have an average of at least 70

first you take 63 and 81 add them together you get 144 then divide by 2 because you have two numbers  then you get 72.which means he got a 66% on his last test here is the work:

63+81+66=210

210 divided by 3=

70%

hope this helps

the equation cos(35) =a/25 can be used to find the length of bc what is the length of bc? round to the nearest tenth

step-by-step explanation:

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116