Answer: 7 years
Step-by-step explanation:
let x be the age of Mary
so John's age will be 2x
the equation becomes
2x+x=21
3x=21
x=21/3
x=7
Answer:
The perimeter of △DEF 43
Step-by-step explanation:
Sin A/ a = Sin B / b = Sin C/ c
sin D/ d =
Sin E / e = sin F /f
sin 52/ e = sin 90 / 18
e = 18 x sin 52 / sin 90
e = 14.184 /1
e = 14.2
From phythagoras theorem ,
/hyp/² = /opp/² + /adj/²
18² = 14.2² + /adj/²
/adj/²= 18² - 14.2²
/adj/² = 324 + 201.64
/adj/² = 119.51
/adj/ = √122.36
= 11.1
Perimeter of Triangle = a + b +c
where a = side
b = base
c = side
Perimeter = 18 + 11.1 + 14.2
Perimeter = 43.3
Perimeter= 43
Answer:
The slope m of a line is one of the elements in the equation of a line when written in the "slope and intercept" form: y = mx+b.
Step-by-step explanation:
Answer:
x = 3
Step-by-step explanation:
The midsegment is half the sum of the parallel bases, that is
= 13 ( multiply both sides by 2 to clear the fraction )
7x + 5 = 26 ( subtract 5 from both sides )
7x = 21 ( divide both sides by 7 )
x = 3