ok so today in class Ms Nicholson gave us some notes to copy about substitution and evaluating an expression.
here are the notes that she gave us:
*in polynomials if a number is substituted into an expression for the variable, then the expression has a value. This is called "evaluating an expression".
after copying the notes she gave us, she gave us a problem to solve about the notes that we just copied.
Here's the problem: evaluate the following polynomial expression if b = 3
-4b2 + 8b - 5
to solve this problem we have to follow two steps.
step 1 : substitute 3 in for every b. which will give us:
-4(3)2+ 8(3) - 5
step 2 : use PEDMAS to find the value of the expression:
= -4(3)2 + 8(3) - 5
= -4(9) + 8(3) - 5
= -36 + 24 - 5
= -12 - 5
= -17
so the value of this expression is -17,
-17 is the answer for this problem.
after doing that Ms Nicholson asked us to group up so that we can pick the top 3 gifts that we are going to donate to the children in Africa, and the top 3 gifts that we have picked are, warm blankets, mosquito nets and seeds of a coconut tree.
and that ends my scribe for today...... hope that you understand it.
Labels: michael
Lol good job michael ;) keep it up ! well i see you don't know how to use exponents in your work, so i'll edit it for you!
value of b = 3
-4b² + 8b - 5
= -4(3)² + 8(3) - 5
= -4(9) + 8(3) - 5
= -36 + 24 - 5
= -12 - 5
= -17
edited by aLisa December 4, 2007