Algebra: Chapter 13, Lesson 7, page 602.
Using Quadratic Equations
Word problems need to be thought out before starting. Draw pictures and understand what information you know and what you need to find out. With DRT problems, you may need to manipulate the `D * R = T` to put it in terms of what you know. Equivalent equations are `R = T/D` and `D = T/R`.
The Pythagorean theorem will also come in handy for these types of problems! REMEMBER, `c^2 = a^2 + b^2`
Once you have the equation, it is probably going to be quadratic and you may have to come up with an LCM. Use all factors in the denominators and you should be fine.
Two of tonight’s homework problems solved by MrE are here! Just click it.
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Algebra 1a: CST Review – SURFACE AREA
Don’t forget SURFACE AREA of RECTILINEAR PRISMS and CYLINDERS!
For cubes and rectangles: AREA, `A = l * w` and multiply by `2`, the number of IDENTICAL FACES and then add them up.
For cylinders, find the lateral area (the side) and the lids:
AREA of LIDS: Area, `A = π* r^2`, there are usually 2 of these
LATERAL AREA: The length * width (or height) of the ‘unrolled paper tube’. The length is the circumference of the circle and the width is the height of the tube. So …
LATERAL AREA: `A = h * (2π *r)`