Answer: 2 9/10 or 2.9 metres
Step-by-step explanation: Form an equation with the information given
1 2/5 + 2 7/10 +x =7
Let x represent the height of Keith
Change mixed fractions into improper fractions
1 2/5=7/5 as an improper fraction we say 1*5+2=7 and put it over the denominator 5
2 7/10 =27/10 as an improper fraction we say 2*10+7 =27 and put it over the denominator 10
we now have the following:
7/5+27/10+x=7
We simplify these fractions by adding them up
7/5
7/5*2/2+27/10=14/10+27/10=41/10
41/10+x=7
To solve for x
take 41/10 from both sides
7-41/10
Making the denominators the same we get the following:
x=70/10-41/10=29/10=2 9/10