Write and solve equation to find value of x?

(99 + 86 + 76 + 95 + x)/5 = 91

multiply both sides by 5:

356 + x = 455

subtract 356 from both sides:

x = 99

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You have five numbers. The sum of those divided by 5 equals 91.

(99 + 86 + 76 + 95 + x)/5 = 91 The rule is you can do any valid operation on both sides of an equation and it will still be equal. So lets multiply by 5.

99 + 86 + 76 + 95 + x = 455 Do the addition.

356 + x = 455 Subtract 356

x = 99

The mean of those 5 numbers is 91?

(1/5)(99 + 86 + 76 + 95 + x) = 91

356 + x = 5•91 = 455

x = 455–356 = 99

check 99 + 86 + 76 + 95 + 99 = 455

455/5 = 91

ok

(99+86+76+95+x)/5 = 91

x = 5*91 - 99 - 86 - 76 - 95 = 99

here given

mean=91

number,n=5

then,

mean=(99+86+76+95+x)/5

91=(356+x)/5

91*5=356+x

455=356+x

x=455-356

x=99 ans.

Total = 5*91 = 455

x = 455 - 356 = 99