3x-10=x+4 is the equation...
To find the average, you have to add all the numbers up and then divide by the amount of numbers you added together.
Equation: (86+87+91+x)/4=98
Solve for x:
86+87+91+x=98*4
264+x=392
x=392-264
x=128
The fourth number is 128
<span>π<span>r^2</span></span><span>h/<span>3
this is a formula if it is a right angle cone
</span></span>π(4)^2 (9)/3
exponent, 4^2 then times by π
<span>after times by (9/3)=
≈150.8
I think, double check and see if right</span>
X = -1 and -1.5 so the 4th answer