Let the actual heights of Lisa, Ian and Jim be L, I and J.
i) "Lisa is 4 centimeters taller than her friend Ian." means: L=4+I
ii) "Ian is 8 centimeters taller than Jim." means: I=8+J, thus J=I-8
so the heights of Lisa, Ian and Jim are 4+I, I and I-8, respectively.
Since their heights increase by 2 cm, in 4 months, their heights increase 2 cm*4 = 8 cm.
Thus, after 4 months the heights of Lisa, Ian and Jim become:
4+I +8, I+8 and I-8+8 that is I + 12, I+8, I.
In 4 months, "the sum of Ian's and Jim's heights will be 140 centimeters more than Lisa's height. " mean:
(I+8)+I=140+(I+12)
2I+8=152+I
I=152-8=144
This solution made use of writing all the ages in terms of Ians current age.
Step-by-step explanation:
factor 4 out of the variable terms, as this helps.
but my approach is simply to define the target and then calculate "backwards".
we want to find
(ax + b)² = a²x² + 2abx + b²
and now we compare with the original equation :
a²x² = 4x²
a² = 4
a = 2
2abx = 16x
2×2×bx = 16x
4b = 16
b = 4
b² = 16, but we have only 3, so we need to subtract 16-3 = 13 from the completed square.
so, our equation is
(2x + 4)² - 13 = 0
(2x + 4)² = 13
2x + 4 = sqrt(13)
2x = sqrt(13) - 4
x = sqrt(13)/2 - 2
Answer:
b, c, d
Step-by-step explanation:
I just took the test
Answer:
14.4 in
Step-by-step explanation:
2160/ 150= 14.4
Answer:
x= 13
Step-by-step explanation:
Please see attached picture for full solution.
Points are labelled with alphabets so it's easier to understand.