6×7=42 so the number missing is 42
They are algebraic symbols or known as unknown number. There is no true value for them. The value of algebraic symbols are based on equations
ie. 1+x = 2
First, we isolate the x by canceling the +1 FROM BOTH SIDES(Balance method) by -1 ON BOTH SIDES.
1+x-1 = 2-1
So we are left with the x on the left side, and a single number on the right side. Therefore, our calculation is complete.
x = 1
More complex cases would be
2y-3 = 45
First, we need to isolate the algebraic symbol, which is 2y (yx2) by +3 ON BOTH SIDES
2y-3+3 = 45+3
2y = 48
WE ARE NOT DONE! 2y=48 is still an equation. Therefore, to isolate the y, we need to divide BOTH SIDES by 2
2y/2 = 48/2
y = 24
There is no true or absolute or definite value for algebraic symbols like x,y,z,a,c,t,h,d etc. They are used to represent unknown numbers.
Hope this helped!
If the train travels 744 miles in 3 hours then to determine the unit rate the train is traveling per hour you have to divide the miles by the hours, in this case (744 miles)/(3 hours). The final result concludes as 248 miles per hour.
Answer:
As shown in picture, this is a trapezoid.
The area of a trapezoid is calculated by:
A = (base1 + base2) x height x (1/2)
To work out A, we need to find out base1, base2, and height.
base1 = YZ = 
base2 = XW =
Otherwise, the height (distance between base1 and base2) is 4 as shown in picture.
=> A = (3 + 7) x 4 x (1/2) = 20
Hope this helps!
:)