Stephen evaluated (6.34 x 10^-7)(4.5 x 10^3). his work is shown below. which statements describe his errors? check all that apply. (6.34 x 10^-7)(4.5 x 10^3) (6.34 x 4.5)(10^-7 x 10^3) 28.53 x 10^-4 -28.53 x 10^4 -2.853 x 10^3 a. he changed the sign of the coefficient. a negative exponent does not affect the sign of a coefficient in scientific notation. the sign of the exponent determines the direction the decimal is moved in. b. he rewrote -28.53 x 10^4 incorrectly; 28.53 x 10^4 = 2.853 x 10^5. the exponent is increased to account for the extra place the decimal is moved. c. he did not correctly evaluate the exponent. it should be evaluated as (10^-7 x 10^3) = 10^3 since exponents are evaluated using the same operation as the coefficients. d. he got the wrong value for the coefficients; 28.53 x 10^-4 is not possible. the coefficients in scientific notation are always greater than 1, but less than 10. f. he multiplied the coefficients; he should have added 6.34 and 4.5. the product of powers rule states that coefficients are added. keep in mind that there is multiple answers.

 A. He changed the sign of the coefficient. A negative exponent does not affect the sign of a coefficient in scientific notation. The sign of the exponent determines the direction the decimal is moved in.

B. He rewrote incorrectly; . The exponent is increased to account for the extra place the decimal is moved.

Step-by-step explanation:

Given expression :

[Taking coefficients and exponents separate]

[By law of exponent]

Here he changed the sign of the coefficient. A negative exponent does not affect the sign of a coefficient in scientific notation. The sign of the exponent determines the direction the decimal is moved in.

Convert in scientific form.

In the given explanation he rewrote incorrectly; . The exponent is increased to account for the extra place the decimal is moved.

Thus, option A and B express the errors done by Stephen.

where did you get them? if you picked from the grass, is is probably poisonous.

step-by-step explanation:

to determine the unit cost your would divide the total cost by the number sold.

7 bagels for $4.41       $4.41/7 = $.63 each at fresh side

5 bagels for $3.60         $3.60/5 = $.72 each at value mart