Answer:
.40 x = 35 equation
x = 87.5
Step-by-step explanation:
Of means multiply and is means equals
40% * x = 35
Change percent to decimal form
.40 x = 35
Divide each side by .40
.40x/.40 = 35/.40
x = 35/.40
x =87.5
Answer:
Yes
Step-by-step explanation:
90% of 50 is 40 so if more than 40 left before it hit 60 seconds then the 90% has been achieved.
Answer:
x is 55 and the perimeter is 120
Step-by-step explanation:
55+55 is 110 and 5+5 is 10 so that all adds up to 120
Answer:
x=14.87
Step-by-step explanation:
What we want to use is pythagoras theorem:
a^2+b^2=c^2, where c is the hypotenuse
10^2+11^2=x^2
221=x^2
x=
x=14.866...
x=14.87
Step-by-step explanation:
the error:
it is stated that
subtract (5x)/(x+7) from both sides
multiply both sides by x + 7
7(x+7) = 49x
7x + 49 = 49x
subtract 7x from both sides to isolate x and its coefficient
49 = 42x
thus, this is only true when 49 = 42x. in order for these two equations to be equal, they must <em>always </em>be true, so this is wrong
the solution:
we want to express 7/x as (something) / (x+7). to do this, we can multiply 7/x by 1.
anything divided by itself = 1. thus, if we multiply both the numerator and the denominator by something that turns x into (x+7), we can do what we want to do.
(x+7)/x * x turns x into (x+7), so we multiply both the numerator and denominator by (x+7)/x to get
substitute this for 7/x in our original problem