-5 1/2 + 6 3/4+ (-4 1/4)= -3
Answer:
12,500,000. You simply move the decimal point over to the right 7 times.
Answer:
15 years old
Step-by-step explanation:
Start by defining the variables that we are going to use throughout our working:
Let the current age of Wei Ling and Wei Xuan be L and X years old respectively.
Next, form equations using the given information.
<u>5 years </u><u>ago</u>
Wei Ling: (L -5) years old
Wei Xuan: (X -5) years old
Given that the ratio of Wei Ling's age to that of Wei Xuan's is 2: 5,

Cross multiply:
2(X -5)= 5(L -5)
Expand:
2X -10= 5L -25
2X= 5L -25 +10
2X= 5L -15 -----(1)
<u>9 years time</u>
Wei Ling: (L +9) years old
Wei Xuan: (X +9) years old
Given that the ratio of Wei Ling's age to that of Wei Xuan is 3: 4,

Cross multiply:
3(X +9)= 4(L +9)
Expand:
3X +27= 4L +36
3X= 4L +36 -27
3X= 4L +9 -----(2)
Let's solve using the elimination method.
(1) ×3:
6X= 15L -45 -----(3)
(2) ×2:
6X= 8L +18 -----(4)
(3) -(4):
6X -6X= 15L -45 -(8L +18)
0= 15L -45 -8L -18
0= 7L -63
7L= 63
L= 63 ÷7
L= 9
Substitute L= 9 into (1):
2X= 5(9) -15
2X= 45 -15
2X= 30
X= 30 ÷2
X= 15
Thus, Wei Xuan is 15 years old now.
Answer:
11.4 metres
Step-by-step explanation:
Use Pythagoras theorem for a right-angled triangle
a^2 + b^2 = c^2
if you cut the rectangle in half, it will become a right angled triangle.
a and b are two sides of the rectangle, while c is the diagonal or hypothenuse
so 9^2 + 7^2 = c^2
81 + 49 = c^2
c^ 2 = 130
square root 130 = c
you should get approximately 11.4 metres
Try this suggested example.
PS. the 1st step is marked with red, the 2d step - with green, the 3d step - with blue colours, then the final step is marked with orange.